diff --git a/Source/FolioReaderAddHighlightNote.swift b/Source/FolioReaderAddHighlightNote.swift
index a4b7af710..b7cbc9e1b 100644
--- a/Source/FolioReaderAddHighlightNote.swift
+++ b/Source/FolioReaderAddHighlightNote.swift
@@ -67,7 +67,7 @@ class FolioReaderAddHighlightNote: UIViewController {
         
         if !highlightSaved && !isEditHighlight {
             guard let currentPage = folioReader.readerCenter?.currentPage else { return }
-            currentPage.webView?.js("removeThisHighlight()")
+            currentPage.webView?.js("removeThisHighlight()") { _ in }
         }
     }
     
diff --git a/Source/FolioReaderAudioPlayer.swift b/Source/FolioReaderAudioPlayer.swift
index 053fc929f..e59a8fd0f 100644
--- a/Source/FolioReaderAudioPlayer.swift
+++ b/Source/FolioReaderAudioPlayer.swift
@@ -176,7 +176,7 @@ open class FolioReaderAudioPlayer: NSObject {
     @objc func play() {
         if book.hasAudio {
             guard let currentPage = self.folioReader.readerCenter?.currentPage else { return }
-            currentPage.webView?.js("playAudio()")
+            currentPage.webView?.js("playAudio()") { _ in }
         } else {
             self.readCurrentSentence()
         }
@@ -382,22 +382,27 @@ open class FolioReaderAudioPlayer: NSObject {
         }
 
         let playbackActiveClass = book.playbackActiveClass
-        guard let sentence = currentPage.webView?.js("getSentenceWithIndex('\(playbackActiveClass)')") else {
-            if (readerCenter.isLastPage() == true) {
-                self.stop()
-            } else {
-                readerCenter.changePageToNext()
+        
+        currentPage.webView?.js("getSentenceWithIndex('\(playbackActiveClass)')") { sentence in
+            guard let sentence = sentence else {
+                if (readerCenter.isLastPage() == true) {
+                    self.stop()
+                } else {
+                    readerCenter.changePageToNext()
+                }
+                return
+                
             }
-
-            return
-        }
-
-        guard let href = readerCenter.getCurrentChapter()?.href else {
-            return
+            
+            guard let href = readerCenter.getCurrentChapter()?.href else {
+                return
+            }
+            
+            // TODO QUESTION: The previous code made it possible to call `playText` with the parameter `href` being an empty string. Was that valid? should this logic be kept?
+            self.playText(href, text: sentence)
+            
         }
-
-        // TODO QUESTION: The previous code made it possible to call `playText` with the parameter `href` being an empty string. Was that valid? should this logic be kept?
-        self.playText(href, text: sentence)
+        
     }
 
     func readCurrentSentence() {
@@ -410,7 +415,7 @@ open class FolioReaderAudioPlayer: NSObject {
             if synthesizer.isSpeaking {
                 stopSynthesizer(immediate: false, completion: {
                     if let currentPage = self.folioReader.readerCenter?.currentPage {
-                        currentPage.webView?.js("resetCurrentSentenceIndex()")
+                        currentPage.webView?.js("resetCurrentSentenceIndex()") { _ in }
                     }
                     self.speakSentence()
                 })
diff --git a/Source/FolioReaderCenter.swift b/Source/FolioReaderCenter.swift
index 6c889f036..f8b5c5a66 100644
--- a/Source/FolioReaderCenter.swift
+++ b/Source/FolioReaderCenter.swift
@@ -648,12 +648,21 @@ open class FolioReaderCenter: UIViewController, UICollectionViewDelegate, UIColl
         }
 
         scrollScrubber?.setSliderVal()
-
-        if let readingTime = currentPage.webView?.js("getReadingTime()") {
-            pageIndicatorView?.totalMinutes = Int(readingTime)!
-        } else {
-            pageIndicatorView?.totalMinutes = 0
+        
+        currentPage.webView?.js("getReadingTime()") { readingTime in
+            
+            guard let readingTime = readingTime
+                else {
+                    self.pageIndicatorView?.totalMinutes = 0
+                    return
+                    
+            }
+            
+            self.pageIndicatorView?.totalMinutes = Int(readingTime)!
+            
         }
+
+
         pagesForCurrentPage(currentPage)
 
         delegate?.pageDidAppear?(currentPage)
@@ -1075,60 +1084,66 @@ open class FolioReaderCenter: UIViewController, UICollectionViewDelegate, UIColl
     @objc func shareChapter(_ sender: UIBarButtonItem) {
         guard let currentPage = currentPage else { return }
 
-        if let chapterText = currentPage.webView?.js("getBodyText()") {
+        
+        currentPage.webView?.js("getBodyText()") { chapterText in
+            
+            guard let chapterText = chapterText else { return }
+            
             let htmlText = chapterText.replacingOccurrences(of: "[\\n\\r]+", with: "<br />", options: .regularExpression)
-            var subject = readerConfig.localizedShareChapterSubject
+            var subject = self.readerConfig.localizedShareChapterSubject
             var html = ""
             var text = ""
             var bookTitle = ""
             var chapterName = ""
             var authorName = ""
             var shareItems = [AnyObject]()
-
+            
             // Get book title
             if let title = self.book.title {
                 bookTitle = title
                 subject += " “\(title)”"
             }
-
+            
             // Get chapter name
-            if let chapter = getCurrentChapterName() {
+            if let chapter = self.getCurrentChapterName() {
                 chapterName = chapter
             }
-
+            
             // Get author name
             if let author = self.book.metadata.creators.first {
                 authorName = author.name
             }
-
+            
             // Sharing html and text
             html = "<html><body>"
             html += "<br /><hr> <p>\(htmlText)</p> <hr><br />"
-            html += "<center><p style=\"color:gray\">"+readerConfig.localizedShareAllExcerptsFrom+"</p>"
+            html += "<center><p style=\"color:gray\">"+self.readerConfig.localizedShareAllExcerptsFrom+"</p>"
             html += "<b>\(bookTitle)</b><br />"
-            html += readerConfig.localizedShareBy+" <i>\(authorName)</i><br />"
-
-            if let bookShareLink = readerConfig.localizedShareWebLink {
+            html += self.readerConfig.localizedShareBy+" <i>\(authorName)</i><br />"
+            
+            if let bookShareLink = self.readerConfig.localizedShareWebLink {
                 html += "<a href=\"\(bookShareLink.absoluteString)\">\(bookShareLink.absoluteString)</a>"
                 shareItems.append(bookShareLink as AnyObject)
             }
-
+            
             html += "</center></body></html>"
-            text = "\(chapterName)\n\n“\(chapterText)” \n\n\(bookTitle) \n\(readerConfig.localizedShareBy) \(authorName)"
-
+            text = "\(chapterName)\n\n“\(chapterText)” \n\n\(bookTitle) \n\(self.readerConfig.localizedShareBy) \(authorName)"
+            
             let act = FolioReaderSharingProvider(subject: subject, text: text, html: html)
             shareItems.insert(contentsOf: [act, "" as AnyObject], at: 0)
-
+            
             let activityViewController = UIActivityViewController(activityItems: shareItems, applicationActivities: nil)
             activityViewController.excludedActivityTypes = [UIActivity.ActivityType.print, UIActivity.ActivityType.postToVimeo]
-
+            
             // Pop style on iPad
             if let actv = activityViewController.popoverPresentationController {
                 actv.barButtonItem = sender
             }
-
-            present(activityViewController, animated: true, completion: nil)
+            
+           self.present(activityViewController, animated: true, completion: nil)
+            
         }
+        
     }
 
     /**
diff --git a/Source/FolioReaderHighlightList.swift b/Source/FolioReaderHighlightList.swift
index 16986a4c8..b2a804ee7 100644
--- a/Source/FolioReaderHighlightList.swift
+++ b/Source/FolioReaderHighlightList.swift
@@ -190,7 +190,7 @@ class FolioReaderHighlightList: UITableViewController {
 
             if (highlight.page == self.folioReader.readerCenter?.currentPageNumber),
                 let page = self.folioReader.readerCenter?.currentPage {
-                Highlight.removeFromHTMLById(withinPage: page, highlightId: highlight.highlightId) // Remove from HTML
+                Highlight.removeFromHTMLById(withinPage: page, highlightId: highlight.highlightId) { _ in } // Remove from HTML
             }
 
             highlight.remove(withConfiguration: self.readerConfig) // Remove from Database
diff --git a/Source/FolioReaderKit.swift b/Source/FolioReaderKit.swift
index 96914b6ef..f6cd5bc79 100755
--- a/Source/FolioReaderKit.swift
+++ b/Source/FolioReaderKit.swift
@@ -185,7 +185,7 @@ extension FolioReader {
 
             if let readerCenter = self.readerCenter {
                 UIView.animate(withDuration: 0.6, animations: {
-                    _ = readerCenter.currentPage?.webView?.js("nightMode(\(self.nightMode))")
+                    _ = readerCenter.currentPage?.webView?.js("nightMode(\(self.nightMode))") { _ in }
                     readerCenter.pageIndicatorView?.reloadColors()
                     readerCenter.configureNavBar()
                     readerCenter.scrollScrubber?.reloadColors()
@@ -210,7 +210,7 @@ extension FolioReader {
         }
         set (font) {
             self.defaults.set(font.rawValue, forKey: kCurrentFontFamily)
-            _ = self.readerCenter?.currentPage?.webView?.js("setFontName('\(font.cssIdentifier)')")
+            _ = self.readerCenter?.currentPage?.webView?.js("setFontName('\(font.cssIdentifier)')") { _ in }
         }
     }
 
@@ -232,7 +232,7 @@ extension FolioReader {
                 return
             }
 
-            currentPage.webView?.js("setFontSize('\(currentFontSize.cssIdentifier)')")
+            currentPage.webView?.js("setFontSize('\(currentFontSize.cssIdentifier)')") { _ in }
         }
     }
 
diff --git a/Source/FolioReaderPage.swift b/Source/FolioReaderPage.swift
index 5b013a0fd..3833bcfc2 100755
--- a/Source/FolioReaderPage.swift
+++ b/Source/FolioReaderPage.swift
@@ -9,6 +9,7 @@
 import UIKit
 import SafariServices
 import MenuItemKit
+import WebKit
 
 /// Protocol which is used from `FolioReaderPage`s.
 @objc public protocol FolioReaderPageDelegate: class {
@@ -35,9 +36,9 @@ import MenuItemKit
     @objc optional func pageTap(_ recognizer: UITapGestureRecognizer)
 }
 
-open class FolioReaderPage: UICollectionViewCell, UIWebViewDelegate, UIGestureRecognizerDelegate {
+open class FolioReaderPage: UICollectionViewCell, WKNavigationDelegate, UIGestureRecognizerDelegate {
     weak var delegate: FolioReaderPageDelegate?
-    weak var readerContainer: FolioReaderContainer?
+    var readerContainer: FolioReaderContainer?
 
     /// The index of the current page. Note: The index start at 1!
     open var pageNumber: Int!
@@ -80,13 +81,12 @@ open class FolioReaderPage: UICollectionViewCell, UIWebViewDelegate, UIGestureRe
         if webView == nil {
             webView = FolioReaderWebView(frame: webViewFrame(), readerContainer: readerContainer)
             webView?.autoresizingMask = [.flexibleWidth, .flexibleHeight]
-            webView?.dataDetectorTypes = .link
             webView?.scrollView.showsVerticalScrollIndicator = false
             webView?.scrollView.showsHorizontalScrollIndicator = false
             webView?.backgroundColor = .clear
             self.contentView.addSubview(webView!)
         }
-        webView?.delegate = self
+        webView?.navigationDelegate = self
 
         if colorView == nil {
             colorView = UIView()
@@ -110,7 +110,7 @@ open class FolioReaderPage: UICollectionViewCell, UIWebViewDelegate, UIGestureRe
 
     deinit {
         webView?.scrollView.delegate = nil
-        webView?.delegate = nil
+        webView?.navigationDelegate = nil
         NotificationCenter.default.removeObserver(self)
     }
 
@@ -186,129 +186,156 @@ open class FolioReaderPage: UICollectionViewCell, UIWebViewDelegate, UIGestureRe
         }
         return tempHtmlContent as String
     }
-
-    // MARK: - UIWebView Delegate
-
-    open func webViewDidFinishLoad(_ webView: UIWebView) {
+    
+    // MARK: - WKNavigationDelegate
+    
+    public func webView(_ webView: WKWebView, didCommit navigation: WKNavigation!) {
         guard let webView = webView as? FolioReaderWebView else {
             return
         }
-
+        
         delegate?.pageWillLoad?(self)
-
+        
         // Add the custom class based onClick listener
         self.setupClassBasedOnClickListeners()
-
+        
         refreshPageMode()
-
+        
         if self.readerConfig.enableTTS && !self.book.hasAudio {
-            webView.js("wrappingSentencesWithinPTags()")
-
+            webView.js("wrappingSentencesWithinPTags()") { _ in }
+            
             if let audioPlayer = self.folioReader.readerAudioPlayer, (audioPlayer.isPlaying() == true) {
                 audioPlayer.readCurrentSentence()
             }
         }
-
+        
         let direction: ScrollDirection = self.folioReader.needsRTLChange ? .positive(withConfiguration: self.readerConfig) : .negative(withConfiguration: self.readerConfig)
-
+        
         if (self.folioReader.readerCenter?.pageScrollDirection == direction &&
             self.folioReader.readerCenter?.isScrolling == true &&
             self.readerConfig.scrollDirection != .horizontalWithVerticalContent) {
             scrollPageToBottom()
         }
-
+        
         UIView.animate(withDuration: 0.2, animations: {webView.alpha = 1}, completion: { finished in
             webView.isColors = false
             self.webView?.createMenu(options: false)
         })
-
+        
         delegate?.pageDidLoad?(self)
+        
+        
     }
-
-    open func webView(_ webView: UIWebView, shouldStartLoadWith request: URLRequest, navigationType: UIWebView.NavigationType) -> Bool {
+    
+    public func webView(_ webView: WKWebView, decidePolicyFor navigationAction: WKNavigationAction, decisionHandler: @escaping (WKNavigationActionPolicy) -> Void) {
+        
+        let request = navigationAction.request
         guard
             let webView = webView as? FolioReaderWebView,
             let scheme = request.url?.scheme else {
-                return true
+                decisionHandler(WKNavigationActionPolicy.allow)
+                return
         }
-
-        guard let url = request.url else { return false }
-
+        
+        guard let url = request.url
+            else {
+                decisionHandler(WKNavigationActionPolicy.cancel)
+                return
+        }
+        
         if scheme == "highlight" || scheme == "highlight-with-note" {
             shouldShowBar = false
-
-            guard let decoded = url.absoluteString.removingPercentEncoding else { return false }
+            
+            guard let decoded = url.absoluteString.removingPercentEncoding
+                else {
+                    decisionHandler(WKNavigationActionPolicy.cancel)
+                    return
+            }
             let index = decoded.index(decoded.startIndex, offsetBy: 12)
             let rect = NSCoder.cgRect(for: String(decoded[index...]))
-
+            
             webView.createMenu(options: true)
             webView.setMenuVisible(true, andRect: rect)
             menuIsVisible = true
-
-            return false
+            decisionHandler(WKNavigationActionPolicy.cancel)
+            return
         } else if scheme == "play-audio" {
-            guard let decoded = url.absoluteString.removingPercentEncoding else { return false }
+            guard let decoded = url.absoluteString.removingPercentEncoding
+                else {
+                    decisionHandler(WKNavigationActionPolicy.cancel)
+                    return
+            }
             let index = decoded.index(decoded.startIndex, offsetBy: 13)
             let playID = String(decoded[index...])
             let chapter = self.folioReader.readerCenter?.getCurrentChapter()
             let href = chapter?.href ?? ""
             self.folioReader.readerAudioPlayer?.playAudio(href, fragmentID: playID)
-
-            return false
+            
+            decisionHandler(WKNavigationActionPolicy.cancel)
+            return
         } else if scheme == "file" {
-
+            
             let anchorFromURL = url.fragment
-
+            
             // Handle internal url
             if !url.pathExtension.isEmpty {
                 let pathComponent = (self.book.opfResource.href as NSString?)?.deletingLastPathComponent
                 guard let base = ((pathComponent == nil || pathComponent?.isEmpty == true) ? self.book.name : pathComponent) else {
-                    return true
+                    decisionHandler(WKNavigationActionPolicy.allow)
+                    return
                 }
-
+                
                 let path = url.path
                 let splitedPath = path.components(separatedBy: base)
-
+                
                 // Return to avoid crash
                 if (splitedPath.count <= 1 || splitedPath[1].isEmpty) {
-                    return true
+                    decisionHandler(WKNavigationActionPolicy.allow)
+                    return
                 }
-
+                
                 let href = splitedPath[1].trimmingCharacters(in: CharacterSet(charactersIn: "/"))
                 let hrefPage = (self.folioReader.readerCenter?.findPageByHref(href) ?? 0) + 1
-
+                
                 if (hrefPage == pageNumber) {
                     // Handle internal #anchor
                     if anchorFromURL != nil {
                         handleAnchor(anchorFromURL!, avoidBeginningAnchors: false, animated: true)
-                        return false
+                        decisionHandler(WKNavigationActionPolicy.cancel)
+                        return
                     }
                 } else {
                     self.folioReader.readerCenter?.changePageWith(href: href, animated: true)
                 }
-                return false
+               decisionHandler(WKNavigationActionPolicy.cancel)
+                return
             }
-
+            
             // Handle internal #anchor
             if anchorFromURL != nil {
                 handleAnchor(anchorFromURL!, avoidBeginningAnchors: false, animated: true)
-                return false
+                decisionHandler(WKNavigationActionPolicy.cancel)
+                return
             }
-
-            return true
+            
+            decisionHandler(WKNavigationActionPolicy.allow)
+            return
+            
         } else if scheme == "mailto" {
             print("Email")
-            return true
-        } else if url.absoluteString != "about:blank" && scheme.contains("http") && navigationType == .linkClicked {
+            decisionHandler(WKNavigationActionPolicy.allow)
+            return
+        } else if url.absoluteString != "about:blank" && scheme.contains("http") && navigationAction.navigationType == .linkActivated {
             let safariVC = SFSafariViewController(url: request.url!)
             safariVC.view.tintColor = self.readerConfig.tintColor
             self.folioReader.readerCenter?.present(safariVC, animated: true, completion: nil)
-            return false
+            decisionHandler(WKNavigationActionPolicy.cancel)
+            return
         } else {
             // Check if the url is a custom class based onClick listerner
             var isClassBasedOnClickListenerScheme = false
             for listener in self.readerConfig.classBasedOnClickListeners {
-
+                
                 if scheme == listener.schemeName,
                     let absoluteURLString = request.url?.absoluteString,
                     let range = absoluteURLString.range(of: "/clientX=") {
@@ -323,21 +350,24 @@ open class FolioReaderPage: UICollectionViewCell, UIWebViewDelegate, UIGestureRe
                     }
                 }
             }
-
+            
             if isClassBasedOnClickListenerScheme == false {
                 // Try to open the url with the system if it wasn't a custom class based click listener
                 if UIApplication.shared.canOpenURL(url) {
                     UIApplication.shared.openURL(url)
-                    return false
+                    decisionHandler(WKNavigationActionPolicy.cancel)
+                    return
                 }
             } else {
-                return false
+                decisionHandler(WKNavigationActionPolicy.cancel)
+                return
             }
         }
-
-        return true
+        
+        decisionHandler(WKNavigationActionPolicy.allow)
+        
     }
-
+   
     fileprivate func getEventTouchPoint(fromPositionParameterString positionParameterString: String) -> CGPoint? {
         // Remove the parameter names: "/clientX=188&clientY=292" -> "188&292"
         var positionParameterString = positionParameterString.replacingOccurrences(of: "/clientX=", with: "")
@@ -373,20 +403,24 @@ open class FolioReaderPage: UICollectionViewCell, UIWebViewDelegate, UIGestureRe
         self.delegate?.pageTap?(recognizer)
         
         if let _navigationController = self.folioReader.readerCenter?.navigationController, (_navigationController.isNavigationBarHidden == true) {
-            let selected = webView?.js("getSelectedText()")
             
-            guard (selected == nil || selected?.isEmpty == true) else {
-                return
-            }
-
-            let delay = 0.4 * Double(NSEC_PER_SEC) // 0.4 seconds * nanoseconds per seconds
-            let dispatchTime = (DispatchTime.now() + (Double(Int64(delay)) / Double(NSEC_PER_SEC)))
             
-            DispatchQueue.main.asyncAfter(deadline: dispatchTime, execute: {
-                if (self.shouldShowBar == true && self.menuIsVisible == false) {
-                    self.folioReader.readerCenter?.toggleBars()
+            webView?.js("getSelectedText()") { selected in
+                
+                guard (selected == nil || selected?.isEmpty == true) else {
+                    return
                 }
-            })
+                
+                let delay = 0.4 * Double(NSEC_PER_SEC) // 0.4 seconds * nanoseconds per seconds
+                let dispatchTime = (DispatchTime.now() + (Double(Int64(delay)) / Double(NSEC_PER_SEC)))
+                
+                DispatchQueue.main.asyncAfter(deadline: dispatchTime, execute: {
+                    if (self.shouldShowBar == true && self.menuIsVisible == false) {
+                        self.folioReader.readerCenter?.toggleBars()
+                    }
+                })
+            }
+            
         } else if (self.readerConfig.shouldHideNavigationOnTap == true) {
             self.folioReader.readerCenter?.hideBars()
             self.menuIsVisible = false
@@ -433,19 +467,21 @@ open class FolioReaderPage: UICollectionViewCell, UIWebViewDelegate, UIGestureRe
      */
     open func handleAnchor(_ anchor: String,  avoidBeginningAnchors: Bool, animated: Bool) {
         if !anchor.isEmpty {
-            let offset = getAnchorOffset(anchor)
-
-            switch self.readerConfig.scrollDirection {
-            case .vertical, .defaultVertical:
-                let isBeginning = (offset < frame.forDirection(withConfiguration: self.readerConfig) * 0.5)
-
-                if !avoidBeginningAnchors {
-                    scrollPageToOffset(offset, animated: animated)
-                } else if avoidBeginningAnchors && !isBeginning {
-                    scrollPageToOffset(offset, animated: animated)
+            getAnchorOffset(anchor) { offset in
+                
+                switch self.readerConfig.scrollDirection {
+                case .vertical, .defaultVertical:
+                    let isBeginning = (offset < self.frame.forDirection(withConfiguration: self.readerConfig) * 0.5)
+                    
+                    if !avoidBeginningAnchors {
+                        self.scrollPageToOffset(offset, animated: animated)
+                    } else if avoidBeginningAnchors && !isBeginning {
+                        self.scrollPageToOffset(offset, animated: animated)
+                    }
+                case .horizontal, .horizontalWithVerticalContent:
+                    self.scrollPageToOffset(offset, animated: animated)
                 }
-            case .horizontal, .horizontalWithVerticalContent:
-                scrollPageToOffset(offset, animated: animated)
+                
             }
         }
     }
@@ -458,13 +494,16 @@ open class FolioReaderPage: UICollectionViewCell, UIWebViewDelegate, UIGestureRe
      - parameter anchor: The #anchor id
      - returns: The element offset ready to scroll
      */
-    func getAnchorOffset(_ anchor: String) -> CGFloat {
+    func getAnchorOffset(_ anchor: String, completion: @escaping ((CGFloat) -> ())) {
         let horizontal = self.readerConfig.scrollDirection == .horizontal
-        if let strOffset = webView?.js("getAnchorOffset('\(anchor)', \(horizontal.description))") {
-            return CGFloat((strOffset as NSString).floatValue)
+        
+        webView?.js("getAnchorOffset('\(anchor)', \(horizontal.description))") { strOffset in
+            guard let strOffset = strOffset else {
+                completion(CGFloat(0))
+                return }
+            completion(CGFloat((strOffset as NSString).floatValue))
         }
-
-        return CGFloat(0)
+        
     }
 
     // MARK: Mark ID
@@ -480,7 +519,7 @@ open class FolioReaderPage: UICollectionViewCell, UIWebViewDelegate, UIGestureRe
         }
 
         let playbackActiveClass = self.book.playbackActiveClass
-        currentPage.webView?.js("audioMarkID('\(playbackActiveClass)','\(identifier)')")
+        currentPage.webView?.js("audioMarkID('\(playbackActiveClass)','\(identifier)')") { _ in }
     }
 
     // MARK: UIMenu visibility
@@ -494,11 +533,17 @@ open class FolioReaderPage: UICollectionViewCell, UIWebViewDelegate, UIGestureRe
         }
 
         if !webView.isShare && !webView.isColors {
-            if let result = webView.js("getSelectedText()") , result.components(separatedBy: " ").count == 1 {
+            
+            webView.js("getSelectedText()") { result in
+                
+                guard let result = result, result.components(separatedBy: " ").count == 1 else {
+                    webView.isOneWord = false
+                    return
+                }
+                
                 webView.isOneWord = true
                 webView.createMenu(options: false)
-            } else {
-                webView.isOneWord = false
+                
             }
         }
 
@@ -508,35 +553,34 @@ open class FolioReaderPage: UICollectionViewCell, UIWebViewDelegate, UIGestureRe
     // MARK: ColorView fix for horizontal layout
     @objc func refreshPageMode() {
         guard let webView = webView else { return }
-
+        
         if (self.folioReader.nightMode == true) {
             // omit create webView and colorView
             let script = "document.documentElement.offsetHeight"
-            let contentHeight = webView.stringByEvaluatingJavaScript(from: script)
-            let frameHeight = webView.frame.height
-            let lastPageHeight = frameHeight * CGFloat(webView.pageCount) - CGFloat(Double(contentHeight!)!)
-            colorView.frame = CGRect(x: webView.frame.width * CGFloat(webView.pageCount-1), y: webView.frame.height - lastPageHeight, width: webView.frame.width, height: lastPageHeight)
-        } else {
-            colorView.frame = CGRect.zero
+            
+            webView.js(script) { contentHeight in
+                
+                guard let contentHeight = Int(contentHeight ?? "") else {
+                    self.colorView.frame = CGRect.zero
+                    return
+                }
+                
+                let frameHeight = webView.frame.height
+//                let lastPageHeight = frameHeight * CGFloat(webView.pageCount) - CGFloat(Double(contentHeight!)!)
+//                colorView.frame = CGRect(x: webView.frame.width * CGFloat(webView.pageCount-1), y: webView.frame.height - lastPageHeight, width: webView.frame.width, height: lastPageHeight)
+                
+            }
+            
         }
     }
     
+    
     // MARK: - Class based click listener
     
     fileprivate func setupClassBasedOnClickListeners() {
         for listener in self.readerConfig.classBasedOnClickListeners {
-            self.webView?.js("addClassBasedOnClickListener(\"\(listener.schemeName)\", \"\(listener.querySelector)\", \"\(listener.attributeName)\", \"\(listener.selectAll)\")");
+            self.webView?.js("addClassBasedOnClickListener(\"\(listener.schemeName)\", \"\(listener.querySelector)\", \"\(listener.attributeName)\", \"\(listener.selectAll)\")") { _ in }
         }
     }
     
-    // MARK: - Public Java Script injection
-    
-    /** 
-     Runs a JavaScript script and returns it result. The result of running the JavaScript script passed in the script parameter, or nil if the script fails.
-     
-     - returns: The result of running the JavaScript script passed in the script parameter, or nil if the script fails.
-     */
-    open func performJavaScript(_ javaScriptCode: String) -> String? {
-        return webView?.js(javaScriptCode)
-    }
 }
diff --git a/Source/FolioReaderPageIndicator.swift b/Source/FolioReaderPageIndicator.swift
index fc1960556..60fb1ca16 100644
--- a/Source/FolioReaderPageIndicator.swift
+++ b/Source/FolioReaderPageIndicator.swift
@@ -95,14 +95,14 @@ class FolioReaderPageIndicator: UIView {
             pagesLabel.text = " \(pagesRemaining) " + self.readerConfig.localizedReaderManyPagesLeft
         }
 
-        let minutesRemaining = Int(ceil(CGFloat((pagesRemaining * totalMinutes)/totalPages)))
-        if minutesRemaining > 1 {
-            minutesLabel.text = "\(minutesRemaining) " + self.readerConfig.localizedReaderManyMinutes+" ·"
-        } else if minutesRemaining == 1 {
-            minutesLabel.text = self.readerConfig.localizedReaderOneMinute+" ·"
-        } else {
-            minutesLabel.text = self.readerConfig.localizedReaderLessThanOneMinute+" ·"
-        }
+//        let minutesRemaining = Int(ceil(CGFloat((pagesRemaining * totalMinutes)/totalPages)))
+//        if minutesRemaining > 1 {
+//            minutesLabel.text = "\(minutesRemaining) " + self.readerConfig.localizedReaderManyMinutes+" ·"
+//        } else if minutesRemaining == 1 {
+//            minutesLabel.text = self.readerConfig.localizedReaderOneMinute+" ·"
+//        } else {
+//            minutesLabel.text = self.readerConfig.localizedReaderLessThanOneMinute+" ·"
+//        }
         
         reloadView(updateShadow: false)
     }
diff --git a/Source/FolioReaderPlayerMenu.swift b/Source/FolioReaderPlayerMenu.swift
index 8b2d24434..fb7fda350 100644
--- a/Source/FolioReaderPlayerMenu.swift
+++ b/Source/FolioReaderPlayerMenu.swift
@@ -267,7 +267,7 @@ class FolioReaderPlayerMenu: UIViewController, SMSegmentViewDelegate, UIGestureR
 
         // update the current page style
         if let currentPage = self.folioReader.readerCenter?.currentPage {
-            currentPage.webView?.js("setMediaOverlayStyle(\"\(self.folioReader.currentMediaOverlayStyle.className())\")")
+            currentPage.webView?.js("setMediaOverlayStyle(\"\(self.folioReader.currentMediaOverlayStyle.className())\")") { _ in }
         }
     }
 
diff --git a/Source/FolioReaderWebView.swift b/Source/FolioReaderWebView.swift
index 9c3b7531a..0ec2f26a7 100644
--- a/Source/FolioReaderWebView.swift
+++ b/Source/FolioReaderWebView.swift
@@ -6,10 +6,13 @@
 //  Copyright (c) 2016 Folio Reader. All rights reserved.
 //
 
-import UIKit
+import WebKit
+
+public typealias JSCallback = ((String?) ->())
 
 /// The custom WebView used in each page
-open class FolioReaderWebView: UIWebView {
+open class FolioReaderWebView: WKWebView {
+    
     var isColors = false
     var isShare = false
     var isOneWord = false
@@ -30,15 +33,18 @@ open class FolioReaderWebView: UIWebView {
         guard let readerContainer = readerContainer else { return FolioReader() }
         return readerContainer.folioReader
     }
-
-    override init(frame: CGRect) {
-        fatalError("use init(frame:readerConfig:book:) instead.")
-    }
-
+    
     init(frame: CGRect, readerContainer: FolioReaderContainer) {
         self.readerContainer = readerContainer
-
-        super.init(frame: frame)
+        
+        let configuration = WKWebViewConfiguration()
+        if #available(iOS 10.0, *) {
+            configuration.dataDetectorTypes = .link
+        } else {
+            // Fallback on earlier versions
+            assertionFailure("unsupported iOS version")
+        }
+        super.init(frame: frame, configuration: configuration)
     }
 
     required public init?(coder aDecoder: NSCoder) {
@@ -77,13 +83,15 @@ open class FolioReaderWebView: UIWebView {
 
         let shareImage = UIAlertAction(title: self.readerConfig.localizedShareImageQuote, style: .default, handler: { (action) -> Void in
             if self.isShare {
-                if let textToShare = self.js("getHighlightContent()") {
+                self.js("getHighlightContent()") { textToShare in
+                    guard let textToShare = textToShare else { return }
                     self.folioReader.readerCenter?.presentQuoteShare(textToShare)
                 }
             } else {
-                if let textToShare = self.js("getSelectedText()") {
+                self.js("getSelectedText()") { textToShare in
+                    guard let textToShare = textToShare else { return }
                     self.folioReader.readerCenter?.presentQuoteShare(textToShare)
-
+                    
                     self.clearTextSelection()
                 }
             }
@@ -92,11 +100,13 @@ open class FolioReaderWebView: UIWebView {
 
         let shareText = UIAlertAction(title: self.readerConfig.localizedShareTextQuote, style: .default) { (action) -> Void in
             if self.isShare {
-                if let textToShare = self.js("getHighlightContent()") {
+                self.js("getHighlightContent()") { textToShare in
+                    guard let textToShare = textToShare else { return }
                     self.folioReader.readerCenter?.shareHighlight(textToShare, rect: sender.menuFrame)
                 }
             } else {
-                if let textToShare = self.js("getSelectedText()") {
+                self.js("getSelectedText()") { textToShare in
+                    guard let textToShare = textToShare else { return }
                     self.folioReader.readerCenter?.shareHighlight(textToShare, rect: sender.menuFrame)
                 }
             }
@@ -124,92 +134,117 @@ open class FolioReaderWebView: UIWebView {
     }
 
     func remove(_ sender: UIMenuController?) {
-        if let removedId = js("removeThisHighlight()") {
+        
+        js("removeThisHighlight()") { removedId in
+            guard let removedId = removedId else { return }
             Highlight.removeById(withConfiguration: self.readerConfig, highlightId: removedId)
         }
+
         setMenuVisible(false)
     }
 
     @objc func highlight(_ sender: UIMenuController?) {
-        let highlightAndReturn = js("highlightString('\(HighlightStyle.classForStyle(self.folioReader.currentHighlightStyle))')")
-        let jsonData = highlightAndReturn?.data(using: String.Encoding.utf8)
-
-        do {
-            let json = try JSONSerialization.jsonObject(with: jsonData!, options: []) as! NSArray
-            let dic = json.firstObject as! [String: String]
-            let rect = NSCoder.cgRect(for: dic["rect"]!)
-            guard let startOffset = dic["startOffset"] else {
-                return
-            }
-            guard let endOffset = dic["endOffset"] else {
-                return
-            }
-
-            createMenu(options: true)
-            setMenuVisible(true, andRect: rect)
-
-            // Persist
-            guard
-                let html = js("getHTML()"),
-                let identifier = dic["id"],
-                let bookId = (self.book.name as NSString?)?.deletingPathExtension else {
+        
+        js("highlightString('\(HighlightStyle.classForStyle(self.folioReader.currentHighlightStyle))')") { highlightAndReturn in
+            let jsonData = highlightAndReturn?.data(using: String.Encoding.utf8)
+            
+            do {
+                let json = try JSONSerialization.jsonObject(with: jsonData!, options: []) as! NSArray
+                let dic = json.firstObject as! [String: String]
+                let rect = NSCoder.cgRect(for: dic["rect"]!)
+                guard let startOffset = dic["startOffset"] else {
+                    return
+                }
+                guard let endOffset = dic["endOffset"] else {
                     return
+                }
+                
+                self.createMenu(options: true)
+                self.setMenuVisible(true, andRect: rect)
+                
+                
+                // Persist
+                self.js("getHTML()") { html in
+                    
+                    guard let html = html, let identifier = dic["id"], let bookId = (self.book.name as NSString?)?.deletingPathExtension
+                        else {
+                            return
+                    }
+                    let pageNumber = self.folioReader.readerCenter?.currentPageNumber ?? 0
+                    let match = Highlight.MatchingHighlight(text: html, id: identifier, startOffset: startOffset, endOffset: endOffset, bookId: bookId, currentPage: pageNumber)
+                    let highlight = Highlight.matchHighlight(match)
+                    highlight?.persist(withConfiguration: self.readerConfig)
+                }
+                
+            } catch {
+                print("Could not receive JSON")
             }
-
-            let pageNumber = folioReader.readerCenter?.currentPageNumber ?? 0
-            let match = Highlight.MatchingHighlight(text: html, id: identifier, startOffset: startOffset, endOffset: endOffset, bookId: bookId, currentPage: pageNumber)
-            let highlight = Highlight.matchHighlight(match)
-            highlight?.persist(withConfiguration: self.readerConfig)
-
-        } catch {
-            print("Could not receive JSON")
+            
         }
+        
     }
     
     @objc func highlightWithNote(_ sender: UIMenuController?) {
-        let highlightAndReturn = js("highlightStringWithNote('\(HighlightStyle.classForStyle(self.folioReader.currentHighlightStyle))')")
-        let jsonData = highlightAndReturn?.data(using: String.Encoding.utf8)
         
-        do {
-            let json = try JSONSerialization.jsonObject(with: jsonData!, options: []) as! NSArray
-            let dic = json.firstObject as! [String: String]
-            guard let startOffset = dic["startOffset"] else { return }
-            guard let endOffset = dic["endOffset"] else { return }
-            
-            self.clearTextSelection()
+        js("highlightStringWithNote('\(HighlightStyle.classForStyle(self.folioReader.currentHighlightStyle))')") { highlightAndReturn in
             
-            guard let html = js("getHTML()") else { return }
-            guard let identifier = dic["id"] else { return }
-            guard let bookId = (self.book.name as NSString?)?.deletingPathExtension else { return }
+            let jsonData = highlightAndReturn?.data(using: String.Encoding.utf8)
             
-            let pageNumber = folioReader.readerCenter?.currentPageNumber ?? 0
-            let match = Highlight.MatchingHighlight(text: html, id: identifier, startOffset: startOffset, endOffset: endOffset, bookId: bookId, currentPage: pageNumber)
-            if let highlight = Highlight.matchHighlight(match) {
-                self.folioReader.readerCenter?.presentAddHighlightNote(highlight, edit: false)
+            do {
+                let json = try JSONSerialization.jsonObject(with: jsonData!, options: []) as! NSArray
+                let dic = json.firstObject as! [String: String]
+                guard let startOffset = dic["startOffset"] else { return }
+                guard let endOffset = dic["endOffset"] else { return }
+                
+                self.clearTextSelection()
+                
+                self.js("getHTML()") { html in
+                    
+                    guard let html = html, let identifier = dic["id"], let bookId = (self.book.name as NSString?)?.deletingPathExtension
+                        else {
+                            return
+                    }
+                    
+                    let pageNumber = self.folioReader.readerCenter?.currentPageNumber ?? 0
+                    let match = Highlight.MatchingHighlight(text: html, id: identifier, startOffset: startOffset, endOffset: endOffset, bookId: bookId, currentPage: pageNumber)
+                    if let highlight = Highlight.matchHighlight(match) {
+                        self.folioReader.readerCenter?.presentAddHighlightNote(highlight, edit: false)
+                        
+                    }
+                    
+                }
+            } catch {
+                print("Could not receive JSON")
             }
-        } catch {
-            print("Could not receive JSON")
+            
         }
     }
     
     @objc func updateHighlightNote (_ sender: UIMenuController?) {
-        guard let highlightId = js("getHighlightId()") else { return }
-        guard let highlightNote = Highlight.getById(withConfiguration: readerConfig, highlightId: highlightId) else { return }
-        self.folioReader.readerCenter?.presentAddHighlightNote(highlightNote, edit: true)
+        
+        js("getHighlightId()") { highlightId in
+            guard let highlightId = highlightId, let highlightNote = Highlight.getById(withConfiguration: self.readerConfig, highlightId: highlightId) else { return }
+            self.folioReader.readerCenter?.presentAddHighlightNote(highlightNote, edit: true)
+        }
+   
     }
 
     @objc func define(_ sender: UIMenuController?) {
-        guard let selectedText = js("getSelectedText()") else {
-            return
+        
+        js("getSelectedText()") { selectedText in
+            
+            guard let selectedText = selectedText else { return }
+            
+            self.setMenuVisible(false)
+            self.clearTextSelection()
+            
+            let vc = UIReferenceLibraryViewController(term: selectedText)
+            vc.view.tintColor = self.readerConfig.tintColor
+            guard let readerContainer = self.readerContainer else { return }
+            readerContainer.show(vc, sender: nil)
+            
         }
 
-        self.setMenuVisible(false)
-        self.clearTextSelection()
-
-        let vc = UIReferenceLibraryViewController(term: selectedText)
-        vc.view.tintColor = self.readerConfig.tintColor
-        guard let readerContainer = readerContainer else { return }
-        readerContainer.show(vc, sender: nil)
     }
 
     @objc func play(_ sender: UIMenuController?) {
@@ -241,7 +276,8 @@ open class FolioReaderWebView: UIWebView {
     func changeHighlightStyle(_ sender: UIMenuController?, style: HighlightStyle) {
         self.folioReader.currentHighlightStyle = style.rawValue
 
-        if let updateId = js("setHighlightStyle('\(HighlightStyle.classForStyle(style.rawValue))')") {
+        js("setHighlightStyle('\(HighlightStyle.classForStyle(style.rawValue))')") { updateId in
+            guard let updateId = updateId else { return }
             Highlight.updateById(withConfiguration: self.readerConfig, highlightId: updateId, type: style)
         }
         
@@ -346,10 +382,12 @@ open class FolioReaderWebView: UIWebView {
     
     // MARK: - Java Script Bridge
     
-    @discardableResult open func js(_ script: String) -> String? {
-        let callback = self.stringByEvaluatingJavaScript(from: script)
-        if callback!.isEmpty { return nil }
-        return callback
+    open func js(_ script: String, completion: @escaping JSCallback) {
+        
+        self.evaluateJavaScript(script) { (result, error) in
+            completion(result as? String)
+        }
+
     }
     
     // MARK: WebView
@@ -366,13 +404,13 @@ open class FolioReaderWebView: UIWebView {
         switch self.readerConfig.scrollDirection {
         case .vertical, .defaultVertical, .horizontalWithVerticalContent:
             scrollView.isPagingEnabled = false
-            paginationMode = .unpaginated
+            //paginationMode = .unpaginated
             scrollView.bounces = true
             break
         case .horizontal:
             scrollView.isPagingEnabled = true
-            paginationMode = .leftToRight
-            paginationBreakingMode = .page
+            //paginationMode = .leftToRight
+            //paginationBreakingMode = .page
             scrollView.bounces = false
             break
         }
diff --git a/Source/Models/Highlight+Helper.swift b/Source/Models/Highlight+Helper.swift
index ac6a9aaf5..e37f8dd52 100644
--- a/Source/Models/Highlight+Helper.swift
+++ b/Source/Models/Highlight+Helper.swift
@@ -289,15 +289,11 @@ extension Highlight {
     ///   - page: The page containing the HTML.
     ///   - highlightId: The ID to be removed
     /// - Returns: The removed id
-    @discardableResult public static func removeFromHTMLById(withinPage page: FolioReaderPage?, highlightId: String) -> String? {
-        guard let currentPage = page else { return nil }
+    public static func removeFromHTMLById(withinPage page: FolioReaderPage?, highlightId: String, completion: @escaping JSCallback) {
+        guard let currentPage = page else { return }
+        
+        currentPage.webView?.js("removeHighlightById('\(highlightId)')", completion: completion)
         
-        if let removedId = currentPage.webView?.js("removeHighlightById('\(highlightId)')") {
-            return removedId
-        } else {
-            print("Error removing Highlight from page")
-            return nil
-        }
     }
     
     /**