quirks or no quirks bookmarklet

September 20th, 2006. Tagged: bookmarklets, browsers, gmail, JavaScript

Here's a bookmarklet that will tell you whether or not the browser renders your page in Standards Complaiance Mode or Quirks Mode. The bookmarklet will figure this out for the page as well as for all the frames (and their frames) recursively. Enjoy!


Drag this to your bookmarklets/favorites or right click and add to favorites:

quirks or !quirks

Sample output

Here's a sample output, produced when used in my WordPress backend when writing this post:

As you can see the page has two frames (probably iframes, doesn't matter), one of them is rendered in Standards Compliant Mode (CSS1Compat) the other one is in Quirks Mode (BackCompat). The overall document is CSS1Compat as well. For the frames, if they were named, you would see the name of the frame before the URL brackets.

And this is GMail, wow, lotsa frames, none compliant 😉

The code

The code is pretty simple, just accessing the compatMode of the the document object. Here it is in more human readable form (not one long line like bookmarket code).

var response = 'Document mode: ' + document.compatMode;
function checkFrames(w) {
  if(w.frames && w.frames.length>0){
    for(var i=0;i<w.frames.length;i++){
      var fr=w.frames[i];
      try {
        response+=fr.name +
              ' ('+fr.document.location+') - '+
      } catch (e) {
        response+='Could not access this frame\\n';

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