What’s New in Firefox 21

Firefox has come of age. In version numbers, that is.

Firefox 21 was released on May 14, 2013. If you’ve not received the update, click Help > About Firefox > Check for Updates. Let’s look at the new features you can expect after installation…

<main> Element Support

The HTML5 <main> element was introduced earlier this year and represents the main content of the body of a document or application, i.e. perhaps a wrapper for an article and aside.

It’s simply a container tag and all browsers will render it regardless. Firefox “support” probably means it defaults to a block element rather than inline, but you’ll still require display:block; for other browsers.

Scoped Stylesheets

If you’ve ever included third-party content on your page, you may find it contains CSS code which pollutes your own styles. Scoped stylesheets restricts style rules to the enclosing container without the necessity to use an iframe, e.g.

<article>
	<p>This paragraph is the standard page color.</p>
</article>

<aside>
	<style scoped>
		p { color: red; }
	</style>
	<p>Only paragraphs within this aside element are red.</p>
</aside>

Very useful. Unfortunately, only Firefox supports scoped CSS but IE11 and Chrome (and therefore Opera) should receive the technology soon.

Health Report

A preliminary implementation of the Health Report has been added to version 21. Non-personal Firefox data will be logged in the browser and to a central location including:

  • configuration details, e.g. hardware, OS, browser version, etc.
  • customization details, e.g. add-ons, plugins, options, etc.
  • performance data, e.g. timing of browser events, rendering, etc.
  • wear and tear data, e.g. session age, profile age, crashes, etc

Information is collated in the Health Report which allows you and Mozilla to determine performance issues. To view it, click Help > Firefox Health Report from the menu or enter about:healthreport in the address bar (wohh — I have 3,519 bookmarks … that explains a lot!)

Mozilla are monitoring your browser software rather than your activities or visited sites but, if you have privacy concerns, it can be disabled in the Health Report itself or in Options > Advanced > Data Choices tab > Enable Firefox Health Report.

Three-State Do Not Track

“Do Not Track” (DNT) is a W3C Recommendation implemented in most browsers. A DNT field is sent with every HTTP header which, if set to 1, means the site should prevent the user’s actions being tracked across two or more domains.

Firefox 21 introduces a new “Do not tell” option:

Do Not Track

The option removes the DNT header so a site is not aware of your preference. It’s a minor privacy improvement, but I suspect DNT isn’t being widely implemented at this time.

Social API

My heart sank when I saw this feature. Social media integration has never been successful; ask anyone who used the Flock or Rockmelt browsers. If I want to catch up with friends and colleagues, I can visit a social networking site or use an app — I don’t need Firefox to drip-feed a steady stream of inane drivel!

The Social API provides a sidebar which shows messages from Facebook. Or Cliqz, Mixi and msnNOW – yep — I’d not heard of them either?

Social API

According to Mozilla:

The Social API has endless potential for integrating social networks, e-mail, finance, music, cloud possibilities, services, to-do lists, sports, news and other applications into your Firefox experience.

I’m less convinced. Will it be different to loading a site in the sidebar? Will publishers use the feature if it’s only supported by one browser? Perhaps I’ll be proved wrong but, unless this becomes an HTML5 Recommendation, I’m cynical about its future.

Android Updates

Firefox 21 on Android has received various HTML5 updates and now scores 421 out of 500 on html5test.com.

As well as the Gecko changes detailed above, the new mobile browser also provides:

  • integrated support for the Charis and Open Sans fonts which Mozilla claim is “a more visually appealing and clear reading experience on the Web”
  • the ability to save media files with a long tap
  • access to the recent history via the back and forward buttons
  • a newly-polished interface.

Admittedly, Firefox 21 is less exciting than previous releases but Mozilla continues to evolve the browser at a pace that makes Google look sluggish. See you again in six weeks for Firefox 22.

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  • Mac

    Couldn’t we have the social thing as an optional plugin at least? This overload of useless events (a friend’s dog popped, that distant friend has been drunk last night, the other friend has broken up with his boy friend…) is driving our lives crazy.

    • http://jokeyrhy.me/ Ron

      Precisely. I’d much rather have their built-in developer tools improved to the point of Chrome’s Developer Tools rather than have built-in social crap.

      The only reason a web developer should want to use Firefox is for that 3D layer view. Chrome’s tools are far superior in every other way.

      • http://www.optimalworks.net/ Craig Buckler

        I still prefer Firefox and Firebug for development. I’ve been using them since the start which makes the Webkit Developer Tools feel a little unnatural.

        Some of the new Firefox tools are very good too. There’s some overlap with Firebug, but they’re useful, lightweight, quick and attractive.

  • http://www.itoctopus.com itoctopus

    Am I the only one who thinks that jumping from version 3 to version 21 in a year or so in a software is ridiculous?

    Windows has been there for about 3 decades and now it’s at version 8.

    PS: The latest version of FireFox has some layout issues when centering divs under certain conditions.

  • http://www.dondepiso.com/ David

    I like firefox aurora download the latest version and it works great