Graded Browser Support Update

By YUI TeamJuly 12th, 2011

GBS Changes

Specific changes for this update include:

Browser Test Baseline

Internet Explorer 6.0 7.0 8.0 9.0
Firefox 3.&#0134 4.&#0134 5.&#0134
Chrome &#0134 Latest stable
Safari 5.&#0134 iOS 3.&#0134 iOS 4.&#0134
Webkit Android 2.&#0134


  • The dagger symbol (as in “Firefox 4.†”) indicates that the most-current non-beta version at that branch level receives support.
  • No guidance is given on iOS or Android OS device usage. The recommendation is that you choose the devices that are most representative of your user base for each OS.

Removing Grades from the Browser Test Baseline

This edition of the GBS update represents a departure from our previous updates in that we are moving away from mapping browsers directly to experience grades (e.g. “A-grade” and “C-grade”). Rather than prescribe what user experience is appropriate for which browsers, we’ll focus on defining an efficient baseline test strategy that maximizes test coverage and minimizes the testing surface. For example, IE6’s still-significant global marketshare warrants continued testing; however today’s GBS allows for the IE6 user experience to be different from the IE9 experience.

Removing Operating Systems from the Browser Test Baseline

In order to streamline testing and minimize resource requirements, we no longer specify which operating system should be tested on. The only exception is when the browser is tightly coupled with the OS version, in which case we refer to the OS version rather than the browser version (e.g. “Safari iOS 4″). This allows us to focus test coverage on browser versions, and minimize redudant testing across platforms. Issues with the same browser across versions are negligible, and generally related to higher-level OS differences, such as key handling and available fonts. Code that is known to touch upon cross-platform issues should be tested on as many platforms as possible, but this testing generally can be isolated to the specific issues rather than running a full regression test of all features. We recommend aligning operating system testing priority with your user base.

Why is IE6 Still on the List?

IE6 still has a significant enough global market share to warrant a verified acceptable user experience. One common misconception with the Progressive Enhancement strategy has been that once a browser enters “C-grade” that it becomes “unsupported”, when in fact it really means that it should be delivered the HTML-only experience. Now that we no longer prescribe which browsers receive what experience, this is left for projects to decide based on their users and resources. The GBS focuses on specifying which browsers need a verified usable experience based on factors such as market share and influence. Defining what is “usable” and specifiying acceptable levels of degradation are left for teams to decide. We still promote a simple Progressive Enhancement model, and discourage projects from creating new tiers without accounting for the additional costs in development, testing, and maintenance resources.

GBS Forecast

We expect to make the following changes in the next update:

  • Discontinue coverage for Safari on iOS 3.
  • Add coverage for Webkit on Android 3.
  • Add coverage for Firefox 6.
  • Add coverage for Safari iOS 5.

The GBS Archive


  1. Are you all mad or what? Google doesn’t even support IE7 anymore let alone IE6. Stop supporting outdated browsers.

  2. IE6 still has a significant enough global market share

    How do you define significant? According to StatCounter, IE6 had 3.54% of the market during the last 7 days:

    I appreciate that you want to cover a broad spectrum, but it’s time to let go of IE6. Enterprise applications that require IE6 will still have older versions of YUI available to work with… if those apps are not going to be updated to work with newer browsers, then it’s very unlikely they will be updated to use new YUI features either.

  3. I was wondering if Opera could enter in the grid now. I’m not sure how you create the tests. But with Opera Watir and the WebDriver it becomes a lot easier to do automation. Selenium has included it.

  4. “Defining what is ‘usable’ and specifiying acceptable levels of degradation are left for teams to decide.”

    See ya later IE6!

    *does happy dance*

  5. @wtf

    This does not mean that all features need to be supported.  If the user stats suggest to you that serving a C-grade experience for any of the listed browsers is appropriate, then that is perfectly acceptable.   

    If your project subscribes to Graded Browser Support, its up to you to decide which of the listed browsers receive the A-grade and which receive the C-grade experience.  If you are doing something other than Graded Browser Support, you can continue to define, test, and maintain your own experience tiers.

    See for more about our definition of “support” and to learn about progressive enhancement.

    According to our statistics, IE6 & 7 market share still warrant a verified user-experience.  This does not mean that they will get the “A-grade” experience.

    The main goal of this update is to decouple testing from the development strategy. Its up to you and your team to decide what the experience should be for your product.   We by no means recommend trying to support all features for all of the listed browsers, however we suggest you not deliver a broken experience either.

  6. [Browser support] “is left for projects to decide”.

    That guidance is exactly why I have been following the YUI GBS. Why should I bother considering what the GBS says now that I have to decide support for myself? Basically now all it says “Here is a list or browsers. Go figure out how to support them.” I was already doing that before GBS.

  7. wishes we had real guidance said:
    July 14, 2011 at 11:45 am

    I agree with Jeff – this seems like YUI is backing away from any guidance. Roughly 3 months since IE9 came out, and the only update here is “don’t ask us what to support anymore” and a list of all active browser versions.

    So much for any guidance.

  8. @Jeff, @wishes we had real guidance

    The YUI project currently strives to provide full support for all features in all the baseline browsers. For all practical purposes, the baseline remains our “A-grade” list for now. However, we are evolving our strategy to allow for exceptions when features are incomplete or impossible for a specific browser, and the current notion of grades no longer accommodates these per-feature/per-browser specifications. We plan to provide updates of our progress as we fine-tune our strategy, but this initial change lays the groundwork for the new direction we are heading in.

    As a best practice, we recommend that you strive to provide the same feature set to all listed browsers, and document any exceptions.

  9. The Developer Network page @ needs to be updated. With the move away from assigning experience grades (A, B, C), should that still be referenced on the page? Should it be noted that it is only applicable to earlier versions of the GBS?

  10. @Jenny Thanks for the explanation. I look forward to seeing where you guys take this.

  11. I too have to question the ongoing usefulness of this chart in it’s current format… it would help guide us if we at least knew what market share each browser has, and if that’s up or down on the last GBS report. Currently I’m to assume I need to support IE6 as thoroughly as FireFox 5!

  12. @Steve

    Actually, the grades are still a valid *development* strategy. What we’ve done is decouple the *testing* strategy from grades. So, for instance, your project could still map certain browsers to certain grades (i.e., define IE 6 as a “C-grade browser”), but we longer prescribe a single mapping for every project.

    Alternately, your project may not want to use grades — you may use other ways of defining feature support. Now your project can map your feature support to the “baseline” browsers as it makes sense for your user base.

    Over time, we’d like to move away from grades ourselves, and we’ll be updating the community with our progress as we go. I hope that makes things a little clearer.

  13. One of the advantages of the old GBS was preventing (recurring) long discussions with co-workers and possibly your boss. Which browser needs how much support? Maybe this was the biggest or even the only advantage of GBS.

    With the new GBS, this advantage is (almost) completely gone. We’re back to our time consuming discussions. Too bad.

  14. @Jenny

    Thanks for clarifying the difference.
    That helps quite a lot.

  15. Dave Hodder said:
    July 22, 2011 at 10:48 am

    I’m surprised the section on operating systems and font rendering doesn’t single out the importance of testing IE8 on Windows XP, and Safari on Mac OS X.

    (Later versions of Windows render fonts differently to XP, and of course IE8 is the last version of IE that will run on it. For most websites Safari is probably the most popular Mac web browser, plus it is used on the Mac more than on Windows.)

  16. Just noticed this page isn’t linked onto the main GBS page like previous Quarters, so this discussion is easily accessible to visitors who haven’t come from the original Blog post

  17. “is not easily accessible” I mean :-(

  18. Dear YUI folks,

    When is the next update to be expected ?
    I get lots of question regarding YUI3 with iOS 5,

    Is it going to be before the release of iOS 5 ?

    For example,w e have seen that the scrollview is not working anymore in the new safari (on iOS 5 beta)

    Thanks a lot for your answer :-) cheers!
    Loic Schulé

  19. Hey Loic,

    Re: ScrollView:

    Please file a bug with a test case. We’ve been testing the library on the iOS 5 betas as they come out (iOS5b6 being the last one we tested on), and we haven’t seen any issues, so we’d need a test case to see what’s going on.


  20. Please please update the GBS homepage to a) include a link to this page and b) deprecate the advice it gives on browser grading.

    I just spent several days working up a proposal on browser support, using much of the advice on those pages and now I’m having to review it all :(

  21. The fact that this is a) not linked from the home page (as has been frequently pointed out) and b) includes IE6 (a risible contender for any baseline and made even more so by the statement that it still has a “still significant global marketshare”) undermines the credibility of this entire program.

    Yahoo forecast a removal of IE6 from A grade *more that a year ago* and even that was way too late. Including it now because you are no longer assigning experience grades just confuses the issue. IE6 was released in 1999 for goodness sake! If you are still using it you deserrve to be beaten like a red-headed step child.

  22. When is the next update to the GBS planned? Obviously, Firefox have gone through versions like crazy (are they even using major/minor versions anymore?) and IE6’s market share has fallen beneath Opera’s which is not in the GBS list.

    I think a new version now would help clear all those out.

    Updates seems to happen every 8-9 months, which mean that we are almost there to get a new update of the GBS list.

  23. Is this the most up to date list? Most firefox users are now using Firefox 9 or 10. Should we be realy only testing 3 to 5? I need to create an accurate guidlines based on this. Should I look else where for an accurate standard?

  24. Surely this is well out of date. Whos still using Firefox 3 and 4. And same with Safari, most users are on 5.xx by now!
    Please update this list using stats from the latest 12 months at least!