diff --git a/README.md b/README.md
index 8a4cdc5..0e5647f 100644
--- a/README.md
+++ b/README.md
@@ -1,6 +1,9 @@
+# rsspreview
 
 Firefox has removed support for RSS in versions 64+.
 
 This includes the feed preview feature that was quite useful for some people.
 
 This extension attempts to recreate it.
+
+Download at: https://addons.mozilla.org/en-US/firefox/addon/rsspreview/
diff --git a/background.js b/background.js
index a6cfa8d..1354717 100644
--- a/background.js
+++ b/background.js
@@ -1,43 +1,41 @@
-
 function detectFeed(event) {
+  // force application/rss+xml to text/xml so the browser displays it instead of downloading
+  let isfeed = false;
 
-	// force application/rss+xml to text/xml so the browser displays it instead of downloading
+  for (let header of event.responseHeaders) {
+    if (header.name.toLowerCase() == 'content-type') {
+      header.value = header.value.replace(
+        /application\/(rss|atom)\+xml/,
+        'text/xml'
+      );
+      isfeed = true;
+      break;
+    }
+  }
 
-	var isfeed = false;
+  if (isfeed) {
+    for (let i = 0; i < event.responseHeaders.length; i++) {
+      if (event.responseHeaders[i].name.toLowerCase() == 'cache-control') {
+        event.responseHeaders.splice(i, 1);
+        break;
+      }
+    }
 
-	for (var header of event.responseHeaders) {
-	    if (header.name.toLowerCase() == "content-type") {
-			header.value = header.value.replace(/application\/(rss|atom)\+xml/,'text/xml');
-			isfeed = true;
-			break;
-	    }
-	}
-
-	if (isfeed) {
-
-		for (var i = 0; i < event.responseHeaders.length; i++) {
-		    if (event.responseHeaders[i].name.toLowerCase() == "cache-control") {
-				event.responseHeaders.splice(i, 1);
-				break;
-		    }
-		}
-
-		// don't cache requests we modified
-		// otherwise on reload the content-type won't be modified again
-		event.responseHeaders.push({ name : "Cache-Control", value : "no-cache, no-store, must-revalidate" });
-
-	}
-
-    return {
-        responseHeaders: event.responseHeaders
-    };
+    // don't cache requests we modified
+    // otherwise on reload the content-type won't be modified again
+    event.responseHeaders.push({
+      name: 'Cache-Control',
+      value: 'no-cache, no-store, must-revalidate',
+    });
+  }
 
+  return { responseHeaders: event.responseHeaders };
 }
 
 const browser = window.browser || window.chrome;
 
 browser.webRequest.onHeadersReceived.addListener(
-    detectFeed,
-    { urls: ["<all_urls>"], types: ["main_frame"] },
-    ["blocking", "responseHeaders"]
-)
+  detectFeed,
+  { urls: ['<all_urls>'], types: ['main_frame'] },
+  ['blocking', 'responseHeaders']
+);
diff --git a/preview.css b/preview.css
index ec98acf..c1de137 100644
--- a/preview.css
+++ b/preview.css
@@ -1,5 +1,3 @@
-
-
 html {
   font: 3mm tahoma,arial,helvetica,sans-serif;
   background-color: rgb(240, 240, 240);
@@ -53,8 +51,6 @@ a[href] img {
   margin-bottom: 0;
 }
 
-
-
 #feedTitleContainer {
   margin-inline-start: 0;
   margin-inline-end: .6em;
diff --git a/rsspreview.js b/rsspreview.js
index 6371f85..f7008cb 100644
--- a/rsspreview.js
+++ b/rsspreview.js
@@ -5,322 +5,272 @@
    * it will do nothing next time.
    */
   if (window.hasRun) {
-  	console.log("already run");
+    console.log('already run');
     return;
   }
+
   window.hasRun = true;
 
-  var xml_parser = new XMLSerializer();
-  var html_parser = new DOMParser();
-
+  let xml_parser = new XMLSerializer();
+  let html_parser = new DOMParser();
 
   function xhrdoc(url, type, cb) {
-
-    var xhr = new XMLHttpRequest();
+    let xhr = new XMLHttpRequest();
     xhr.open('GET', url, true);
 
     xhr.responseType = 'document';
     xhr.overrideMimeType('text/' + type);
 
-    xhr.onload = function () {
+    xhr.onload = () => {
       if (xhr.readyState === xhr.DONE) {
         if (xhr.status === 200) {
-          var resp = (type=="xml") ? xhr.responseXML : xhr.response;
+          let resp = type == 'xml' ? xhr.responseXML : xhr.response;
           cb(resp);
         }
       }
     };
 
     xhr.send(null);
-
   }
 
-
-
-  function applyxsl(xmlin, xsl, node, doc=document) {
-    var xsltProcessor = new XSLTProcessor();
+  function applyxsl(xmlin, xsl, node, doc = document) {
+    let xsltProcessor = new XSLTProcessor();
     xsltProcessor.importStylesheet(xsl);
 
-    var fragment = xsltProcessor.transformToFragment(xmlin, doc);
+    let fragment = xsltProcessor.transformToFragment(xmlin, doc);
     node.appendChild(fragment);
-
   }
 
-
   function getlang() {
     if (navigator.languages && navigator.languages[0])
       return navigator.languages[0];
-    else if (navigator.language)
-      return navigator.language;
-    else
-      return null;
+    else if (navigator.language) return navigator.language;
+    else return null;
   }
 
-
   function formatsubtitle() {
-
     try {
-      var feed_desc = document.getElementById("feedSubtitleRaw");
+      let feed_desc = document.getElementById('feedSubtitleRaw');
 
-      var html_desc = html_parser.parseFromString('<h2 id="feedSubtitleText">'+feed_desc.innerText+'</h2>', "text/html");
-      var xml_desc = xml_parser.serializeToString(html_desc.body.firstChild);
+      let html_desc = html_parser.parseFromString(
+        '<h2 id="feedSubtitleText">' + feed_desc.innerText + '</h2>',
+        'text/html'
+      );
+      let xml_desc = xml_parser.serializeToString(html_desc.body.firstChild);
 
       feed_desc.insertAdjacentHTML('afterend', xml_desc);
 
       feed_desc.parentNode.removeChild(feed_desc);
-    }
-    catch (e) {
+    } catch (e) {
       console.error(e);
       console.log(feed_desc.innerText);
     }
-
-
   }
 
-  function formatdescriptions(el=document) {
-
+  function formatdescriptions(el = document) {
     // unescapes descriptions to html then to xml
+    let tohtml = el.getElementsByClassName('feedRawContent');
 
-    var tohtml = el.getElementsByClassName("feedRawContent");
-    for (var i = 0; i<tohtml.length; i++) {
-
+    for (let i = 0; i < tohtml.length; i++) {
       // in case of xhtml the content is already parsed
-      if (tohtml[i].getAttribute("desctype") != "xhtml") {
-
+      if (tohtml[i].getAttribute('desctype') != 'xhtml') {
         try {
-          var html_desc = html_parser.parseFromString('<div class="feedEntryContent">'+tohtml[i].innerText+'</div>', "text/html");
-          var xml_desc = xml_parser.serializeToString(html_desc.body.firstChild);
+          let html_desc = html_parser.parseFromString(
+            '<div class="feedEntryContent">' + tohtml[i].innerText + '</div>',
+            'text/html'
+          );
+          let xml_desc = xml_parser.serializeToString(
+            html_desc.body.firstChild
+          );
 
           tohtml[i].insertAdjacentHTML('afterend', xml_desc);
-          tohtml[i].setAttribute("todel", 1);
-        }
-        catch (e) {
+          tohtml[i].setAttribute('todel', 1);
+        } catch (e) {
           console.error(e);
           console.log(tohtml[i].innerHTML);
         }
       }
-
     }
 
-    el.querySelectorAll('.feedRawContent').forEach(function(a){
-      if (a.getAttribute("todel") == "1") {
+    el.querySelectorAll('.feedRawContent').forEach(a => {
+      if (a.getAttribute('todel') == '1') {
         a.remove();
+      } else if (a.getAttribute('desctype') == 'xhtml') {
+        a.classList.add('feedEntryContent');
+        a.classList.remove('feedRawContent');
       }
-      else if (a.getAttribute("desctype") == "xhtml") {
-        a.classList.add("feedEntryContent");
-        a.classList.remove("feedRawContent");
-      }
-    })
-
+    });
   }
 
+  function removeemptyenclosures(el = document) {
+    let encs = el.getElementsByClassName('enclosures');
 
-
-
-  function removeemptyenclosures(el=document) {
-
-    var encs = el.getElementsByClassName("enclosures");
-    for (var i = 0; i<encs.length; i++) {
-
-      if (!encs[i].firstChild)
-        encs[i].style.display = "none";
-
-    }
-
+    for (let i = 0; i < encs.length; i++)
+      if (!encs[i].firstChild) encs[i].style.display = 'none';
   }
 
-  function formatfilenames(el=document) {
+  function formatfilenames(el = document) {
+    let encfn = el.getElementsByClassName('enclosureFilename');
+
+    for (let i = 0; i < encfn.length; i++) {
+      let url = new URL(encfn[i].innerText);
 
-    var encfn = el.getElementsByClassName("enclosureFilename");
-    for (var i = 0; i<encfn.length; i++) {
-      var url = new URL(encfn[i].innerText);
       if (url) {
-        var fn = url.pathname.split("/").pop();
-        if (fn != "") {
-          encfn[i].innerText = fn;
-        }
+        let fn = url.pathname.split('/').pop();
+
+        if (fn != '') encfn[i].innerText = fn;
       }
-
     }
-
   }
 
-
-  function formatfilesizes(el=document) {
-
+  function formatfilesizes(el = document) {
     function humanfilesize(size) {
-      var i = 0;
-      if (size && size != "" && size > 0)
-        i = Math.floor( Math.log(size) / Math.log(1024) );
-        return ( size / Math.pow(1024, i) ).toFixed(2) * 1 + ' ' + ['B', 'kB', 'MB', 'GB', 'TB'][i];
-    };
+      let i = 0;
 
-    var encsz = el.getElementsByClassName("enclosureSize");
-    for (var i = 0; i<encsz.length; i++) {
-      var hsize = humanfilesize(encsz[i].innerText);
-      if (hsize) {
-        encsz[i].innerText = hsize;
-      }
+      if (size && size != '' && size > 0)
+        i = Math.floor(Math.log(size) / Math.log(1024));
 
+      return (
+        (size / Math.pow(1024, i)).toFixed(2) * 1 +
+        ' ' +
+        ['B', 'kB', 'MB', 'GB', 'TB'][i]
+      );
+    }
+
+    let encsz = el.getElementsByClassName('enclosureSize');
+    for (let i = 0; i < encsz.length; i++) {
+      let hsize = humanfilesize(encsz[i].innerText);
+
+      if (hsize) encsz[i].innerText = hsize;
     }
   }
 
+  function formattitles(el = document) {
+    let et = el.getElementsByClassName('entrytitle');
 
-  function formattitles(el=document) {
-
-    var et = el.getElementsByClassName("entrytitle");
-    for (var i = 0; i<et.length; i++) {
-
+    for (let i = 0; i < et.length; i++) {
       //basically removes html content if there is some
       //only do it if there's a tag to avoid doing it when text titles cointain a '&'
       //(which can be caught but still displays an error in console, which is annoying)
-
       if (et[i].innerText.indexOf('<') >= 0) {
-
-        var tmp = document.createElement("span");
+        let tmp = document.createElement('span');
         try {
           tmp.innerHTML = et[i].innerText;
           et[i].innerText = tmp.textContent;
-        }
-        catch (e) {
+        } catch (e) {
           console.error(e);
           console.log(et[i].innerText);
         }
-
       }
-
     }
-
   }
 
+  function formatdates(el = document) {
+    let lang = getlang();
+    if (!lang) return;
 
+    let opts = {
+      weekday: 'long',
+      year: 'numeric',
+      month: 'long',
+      day: 'numeric',
+    };
 
+    let ed = el.getElementsByClassName('lastUpdated');
+    for (let i = 0; i < ed.length; i++) {
+      let d = new Date(ed[i].innerText);
+      if (isNaN(d)) continue;
 
-  function formatdates(el=document) {
+      let dstr =
+        d.toLocaleDateString(lang, opts) + ' ' + d.toLocaleTimeString(lang);
 
-    var lang = getlang();
-    if (!lang)
-      return;
-
-    var opts = { weekday: 'long', year: 'numeric', month: 'long', day: 'numeric' };
-
-    var ed = el.getElementsByClassName("lastUpdated");
-    for (var i = 0; i<ed.length; i++) {
-
-      var d = new Date(ed[i].innerText);
-      if (isNaN(d))
-        continue;
-
-      var dstr = d.toLocaleDateString(lang, opts) + ' ' + d.toLocaleTimeString(lang);
       ed[i].innerText = dstr;
-
     }
-
   }
 
+  function extensionimages(el = document) {
+    let extimgs = el.getElementsByClassName('extImg');
 
-
-  function extensionimages(el=document) {
-
-    var extimgs = el.getElementsByClassName("extImg");
-    for (var i = 0; i<extimgs.length; i++) {
-      extimgs[i].src = chrome.extension.getURL(extimgs[i].attributes['data-src'].nodeValue);
-    }
-
+    for (let i = 0; i < extimgs.length; i++)
+      extimgs[i].src = chrome.extension.getURL(
+        extimgs[i].attributes['data-src'].nodeValue
+      );
   }
 
   function makepreviewhtml() {
+    let doc = document.implementation.createHTMLDocument('');
 
-    var doc = document.implementation.createHTMLDocument("");
-
-    var feedBody = doc.createElement("div");
-    feedBody.id = "feedBody";
+    let feedBody = doc.createElement('div');
+    feedBody.id = 'feedBody';
     doc.body.appendChild(feedBody);
 
-    var css = doc.createElement('link');
+    let css = doc.createElement('link');
     css.setAttribute('rel', 'stylesheet');
-    css.setAttribute('href', chrome.extension.getURL("preview.css"));
+    css.setAttribute('href', chrome.extension.getURL('preview.css'));
     doc.head.appendChild(css);
 
     return doc;
-
-
   }
 
-
   function detect() {
-
-    var rootNode = document.getRootNode().documentElement;
+    let rootNode = document.getRootNode().documentElement;
 
     // for chrome
-    var d = document.getElementById("webkit-xml-viewer-source-xml");
-    if (d && d.firstChild)
-      rootNode = d.firstChild;
+    let d = document.getElementById('webkit-xml-viewer-source-xml');
+    if (d && d.firstChild) rootNode = d.firstChild;
 
     const rootName = rootNode.nodeName.toLowerCase();
 
+    let isRSS1 = false;
 
-    var isRSS1 = false;
-    if (rootName == "rdf" || rootName == "rdf:rdf") {
-      if (rootNode.attributes['xmlns']) {
-        isRSS1 = (rootNode.attributes['xmlns'].nodeValue.search('rss') > 0)
-      }
-    }
-
-
-    if ( rootName == "rss" || rootName == "channel"  // rss2
-      || rootName == "feed"  // atom
-      || isRSS1 ) {
-
+    if (rootName == 'rdf' || rootName == 'rdf:rdf')
+      if (rootNode.attributes['xmlns'])
+        isRSS1 = rootNode.attributes['xmlns'].nodeValue.search('rss') > 0;
 
+    if (
+      rootName == 'rss' ||
+      rootName == 'channel' || // rss2
+      rootName == 'feed' || // atom
+      isRSS1
+    )
       return rootNode;
 
-    }
-
     return null;
-
   }
 
-
   function main(feedNode) {
+    let feed_url = window.location.href;
+    let preview = makepreviewhtml();
 
-      var feed_url = window.location.href;
+    xhrdoc(chrome.extension.getURL('rss.xsl'), 'xml', xsl_xml => {
+      applyxsl(feedNode, xsl_xml, preview.getElementById('feedBody'), preview);
 
-      var preview = makepreviewhtml();
+      // replace the content with the preview document
+      document.replaceChild(
+        document.importNode(preview.documentElement, true),
+        document.documentElement
+      );
 
-      xhrdoc(chrome.extension.getURL("rss.xsl"), "xml", function(xsl_xml) {
+      let t0 = performance.now();
 
-        applyxsl(feedNode, xsl_xml, preview.getElementById("feedBody"), preview);
-
-        // replace the content with the preview document
-        document.replaceChild(document.importNode(preview.documentElement, true), document.documentElement);
-
-        var t0 = performance.now();
-
-        formatsubtitle();
-
-        formatdescriptions();
-        removeemptyenclosures();
-        formatfilenames();
-        formatfilesizes();
-        formattitles();
-        formatdates();
-        extensionimages();
-
-        var t1 = performance.now();
-        //console.log("exec in: " + (t1 - t0) + "ms");
-
-        document.title = document.getElementById("feedTitleText").innerText;
-
-      });
+      formatsubtitle();
 
+      formatdescriptions();
+      removeemptyenclosures();
+      formatfilenames();
+      formatfilesizes();
+      formattitles();
+      formatdates();
+      extensionimages();
 
+      let t1 = performance.now();
+      //console.log("exec in: " + (t1 - t0) + "ms");
 
+      document.title = document.getElementById('feedTitleText').innerText;
+    });
   }
 
-  var feedRoot = detect();
-
-  if (feedRoot)
-    main(feedRoot);
+  let feedRoot = detect();
 
+  if (feedRoot) main(feedRoot);
 })();