Graded Browser Support Update: Q3 2009

By Eric MiragliaJuly 2nd, 2009

This post announces an update to Graded Browser Support. The GBS page on the YUI site always has the most current information. This post includes a list of changes, the updated chart of browsers that receive A-grade support, and our GBS forecast. The discussion section breaks out some of the strategy behind the current GBS update.

GBS Changes for Q3 2009

This GBS update adds A-grade support for Firefox 3.5 and for Safari 4.0. A-grade support is discontinued for Firefox 2, Opera on Mac OS X, and IE6 on Windows 2000. With this update, Windows 2000 drops from the A-Grade testing matrix and the testing surface is reduced to 14 browsers on 4 OS platforms (down from 15 browsers on 5 platforms).

  • Initiated A-grade support for Firefox 3.5, Windows XP
  • Initiated A-grade support for Firefox 3.5, Windows Vista
  • Initiated A-grade support for Safari 4.0, Mac OS 10.4
  • Initiated A-grade support for Safari 4.0, Mac OS 10.5

  • Discontinued A-grade support for IE6, Windows 2000

  • Discontinued A-grade support for Firefox 3.0, Windows Vista
  • Discontinued A-grade support for Firefox 2.0, Mac OS 10.5
  • Discontinued A-grade support for Firefox 2.0, Windows XP
  • Discontinued A-grade support for Opera 9.6, Mac OS 10.5
Win XP Win Vista Mac 10.4.† Mac 10.5.†
Firefox 3.0.† A-grade A-grade
Firefox 3.5.† A-grade A-grade A-grade
Opera 9.6.† A-grade
IE 8.0 A-grade A-grade
IE 7.0 A-grade A-grade
IE 6.0 A-grade
Safari 3.2.† A-grade
Safari 4.0.† A-grade A-grade


  • The dagger symbol (as in “Firefox 3.5.†”) indicates that the most-current non-beta version at that branch level receives support.
  • Code that may be used on pages with unknown doctypes should be tested in IE7 quirks mode.
  • Code that may appear in IE8′s “compatibility mode,” which emulates but is not identical to IE7, should be tested explicitly in compatibility mode.

GBS Forecast

We expect to make the following changes in the Q4 2009 GBS update:

  • Discontinue A-grade support for Firefox 3.0.x across all OSs.
  • Discontinue A-grade support for Safari 3.2.x on Mac OS 10.5.
  • Begin publication of A-grade matrix for smartphones
  • Re-evaluate status of Google Chrome


  1. Opera's marketshare in eastern Europe.Opera: Opera continues to be an important independent browser manufacturer, but its sub-1% global marketshare is now superseded by other browsers whose user base is growing more rapidly (including Safari on Apple’s iPhone OS and Google’s Chrome on Windows). In many ways, the X-grade browser class, which is full of excellent small-marketshare browsers, is the right category for Opera at this point. However, for developers of global products, Opera’s strong position in Russia and eastern Europe (source: StatCounter) argues persuasively for its continued inclusion in the A-grade. Hence, our advice remains that you continue to test your applications in the latest version of Opera on Windows XP. We’ve dropped A-grade support for Opera on Mac OS 10.x to reduce the testing surface and accommodate future inclusion of browsers with rapidly growing marketshare.
  2. Chrome: One of the most common questions we get about GBS today is: “What about Google Chrome?” It’s a fair question. Chrome is an excellent, innovative browser that adheres to web standards, and it has a rapidly expanding marketshare. Chrome remains an X-grade browser today because its marketshare is still very small on a relative basis. If Chrome maintains its current marketshare growth, it will be reclassified as A-grade within one or two quarters. Note that Google’s developer page for Chrome suggests that “if you’ve tested your website with Safari 3.1 then your site should already work well on Google Chrome.” This is good advice.
  3. Yahoo! Search running on the iPhone OS version of Safari.Safari on the iPhone OS: The OS that drives Apple’s iPhone and iPod Touch devices is another ascendant category of browser traffic. Is Safari for the iPhone OS an A-grade browser? Our answer: No, but that doesn’t mean you can ignore it in your product planning and testing. We regard the emerging class of full-featured browsers on handheld devices to be a category that requires its own GBS matrix. Such a matrix should include testing advice for browsers including Safari on iPhone as well as the browsers that ship with Google’s Android OS and Palm’s Pre OS. Treating these browsers as X-grade today is the right decision based on their marketshare — remember, X-grade browsers are expected to support current web standards and to perform well in browsing well developed sites. But the rapid growth of web traffic coming through these browsers, their unique form factors (much smaller screens), and their new interaction paradigms (including touch-screen gestures) argue for an intentional and sometimes differentiated approach to web-application design and implementation. While most content should “just work” and work well, these devices need to be considered at the product-design stage. Providing an “A-grade” experience for your application may not be a question of whether your app runs in the browser but whether your app’s usability on a small touchscreen retains its usability. With this in mind, we’ll begin delivering a smartphone GBS matrix beginning in Q4 2009.

We’d love to hear your take on these issues and others in the comments section.

The GBS Archive


  1. The term “A-Grade” is a misnomer, despite your intent, and how you try and explain it. It implies that X-Grade browsers are less capable, when in fact in many cases it just means they are less popular. In particular, I think it’s a shame that Opera is moving into the X-Grade category. Their track record of innovation, often ripped off by other vendors (i.e. “Top Sites” == “Speed Dial”), and standards support, plus their commitment to multiple platforms (Google Chrome is a sad joke on that point) makes them far more deserving of an “A-Grade” rating than, for instance, the pitiful excuse of IE6, which should be relegated to C-Grade immediately.

  2. Jason — I think you make a good point about the connotation of the terms “A-grade” and “X-grade.” We do try to explain that it’s not a value judgement — as in the case of Chrome today, which on Windows looks like a very good browser — but the connotations run against that. Keep in mind, though, that GBS is a strategy for QA, and it’s explicitly not a report card. As such, IE6 — which no one considers to be a competitive modern browser — deserves and requires your QA attention simply because so many people still depend on it. I appreciate your comments on Opera’s record of innovation, as well; all good points. -Eric

  3. @JasonHuck,

    Unfortunately the reality is that a great number of web developers are still required (by clients) to support the pitiful excuse that is IE6. I think what Yahoo is doing with their Graded Browser Support is better than the alternatives (ie: not offering any level of support).

  4. Brian LePore said:
    July 2, 2009 at 11:48 am

    Maybe I’m reading it wrong, but why is Safari 3.2 supported on 10.5, but not on 10.4?

  5. Brian — Part of the goal with GBS is to maximize your testing mileage in a sane way — because testing every browser/os combination is expensive. So, we recommend continuing to support 3.2 because 4.0 is so new, but to shift the bulk of your testing resources to 4.0. Safari 4.0.x is now the current browser and a free upgrade on both 10.4 and 10.5, and 10.5 has been out for more than 4 years ( In the real world, the expectation is that your testing of 3.2 on OS 10.5 should give you a good idea of the experience your 10.4 users are having. -Eric

  6. I think the confusion about what A or X grade actually means might stem from statements like this:

    “Is Safari for the iPhone OS an A-grade browser? Our answer: No…”

    The question makes it sound like the capabilities of the browser determine its grade, instead of asking if the browser’s market share warrants A-grade support from YUI (as is the case with IE6).

  7. Josh – Capability and marketshare are both part of the equation. Safari on iPhone OS is a complicated case. In our data, this browser does not yet represent 1% of the market, and nowhere does it penetrate a region the way Opera does with Russia and eastern Europe. Moreover, there are common development hooks that are available on a typical desktop PC but not with a touchscreen-only interface. Does it make sense to drop this browser into the same testing matrix that you use for the big-screen browsers? I respect that not everyone’s answer would be the same on this, and it’s a credit to how good the iPhone is that it’s even an interesting conversation. But our answer today is no — or, at least, not yet. More on our thinking in the post itself. -Eric

  8. I started writing a comment for this post, but it got a smidge lengthy, so I finished it up here.

  9. If you look at StatCounter’s Global Stats for the last month, you will see that the developer preview of Opera Unite really spiked Opera’s market share! ;) At least in Europe.

  10. Just to clarify, as I think Eric understood, I’m not questioning the _rationale_ behind Yahoo’s QA strategy. The sad truth is that, in most cases, we have no choice but to continue supporting IE6 for the foreseeable future.

    However, IMO, when someone with Yahoo’s influence publishes a table like this every quarter and labels certain browsers as “A-Grade”, “C-Grade”, etc., it’s those labels, and the obvious connotations that people derive from them, that persist; the intent behind the data is lost on many.

    That’s only compounded by the fact that there is no _definitive_ counterpart to this list; something that IS, in fact, a rating of a browser’s standards support, performance, and innovation — not just for developers, but for end users. The closest thing I can think of would be ACID test scores, but that’s not a complete evaluation and doesn’t provide specific recommendations.

    It might be interesting to see an organization such as Yahoo! establish evaluation criteria for rating browsers on actual merit instead of unfortunate circumstance — not as part of a QA strategy, but to help drive adoption.

    - jason

  11. How come you claim a sub-1% global market share for Opera, while your source (StatCounter) places it at above 3% globally (and 8% in Europe)?

  12. Mitch — To clarify, we see a sub-1% marketshare for Opera on the Yahoo network in the US. I pointed to StatCounter stats for Russia, for which we don’t have reliable internal data. -Eric

  13. Why is it that IE6 (at 8 years of age) is still A-grade, but you deprecate Firefox 3 immediately upon the release of 3.5? At what point will you finally deprecate IE6 and allow YUI to progress in areas like fixed positioning?

    Not that I don’t appreciate all of your hard work – just musing on the fairness of the situation.

  14. @Jeremy — No one wants to stop supporting IE6 more than we do. The rationale here isn’t we like IE6 or what it involves, but rather that we respect the needs of the users who are stuck on IE6. It’s a huge group of users, and many of them are not able to upgrade — for a variety of reasons. GBS is a testing strategy, not a report card. IE6 is still deserving of A-grade attention and QA cycles. What Twitter and others have been doing in trying to hasten the migration of users off of IE6 is laudable…hopefully we’ll see more of that and an acceleration in the decrease in IE6 use. -Eric

  15. No linux/browser combinations? Perhaps it’s covered elsewhere, but I don’t see a reason why linux would be left off the list on the GBS page.

  16. Dave –

    It’s a question of return on your investment of testing resources. Mozilla browsers on Linux are very similar to their Mac/Windows counterparts — if you’re testing the latter, you’re getting some implicit coverage of the former. Again, GBS is not a scorecard for browser quality…it’s a strategy for supporting users by maximizing the value of testing resources.


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