Graded Browser Support Update

By YUI TeamJanuary 28th, 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 primary changes, the updated chart of browsers that receive A-grade support, and our GBS forecast.

Primary Changes

This GBS update adds A-grade support for IE8 on XP and Vista. A-grade support is discontinued for Firefox 3 on Win 2000 and Mac 10.4, keeping the A-grade testing surface at 15 platforms.

  • Initiated A-grade support for IE 8, Win XP
  • Initiated A-grade support for IE 8, Win Vista

  • Discontinued A-grade support for Firefox 3, Win 2000

  • Discontinued A-grade support for Firefox 3, Mac 10.4

  • Incremented supported version of Opera to 9.6

  • Incremented supported version of Safari to 3.2
Win 2000 Win XP Win Vista Mac 10.4.† Mac 10.5.†
Firefox 3.0.† A-grade A-grade A-grade
Firefox 2.0.† A-grade A-grade
IE 8.0 A-grade A-grade
IE 7.0 A-grade A-grade
IE 6.0 A-grade A-grade
Opera 9.6† A-grade A-grade
Safari 3.2† A-grade A-grade

The dagger symbol (as in “Firefox 3.†”) indicates that the most-current non-beta version at that branch level receives support. Put another way, † means “the most recent” instead of “all.”

GBS Forecast

In addition to the effective-immediately changes, we’re forecasting the discontinuation of A-grade support for Firefox 2 in the GBS update toward the end of June 2009.

The GBS Archive


  1. Sad thing that you totally ignore Linux…

  2. It’s also kind of odd that you continue to ignore Google Chrome. Since Chrome has a higher market share than Opera on Windows, it’s pretty clearly “Identified, capable, modern, and common.” And it’s no longer a beta product. Further, because it has a unique js engine it needs to be tested separately from Safari.

    Is this ego? Yahoo and Google are competitors, so ignore Google’s browser? (In that case, why support IE?)

  3. I think I agree with parts of both comments above.

    Firefox 3 on Linux should be tested, although I’m sure this will be an easy and fast test to run since probably nothing will have to done to specifically support this configuration.

    Google Chrome on Windows XP and Windows Vista should be tested if Opera is being tested. I’d personally be more worried about supporting users with Google Chrome than Opera because a lot of people use Google services and they have plenty of marketing opportunities to push Chrome.

  4. I don’t see anything about it on the main GBS page, but I wonder if the fact that Chrome’s been stable/1.0 for only a month or so has something to do with it? Prior to that it was still in beta, and since the Firefox, Opera and Safari notes all say they’re only for “non-beta” versions…

  5. About Linux:

    As I’ve written repeatedly in the past, we do not “ignore Linux.” Nor do we ignore Chrome, Camino, Flock, SeaMonkey, Maxthon, Bento, IceWeasel, K-Meleon, iCab, Konqueror, Shiira and the many-thousand others that visit Yahoo! every day.

    In fact, the spark for the GBS framework was an urgent desire to support all users.

    Browsers not on the A-grade list—nor identified as incapable—are provided X-grade support. The only practical difference between A- and X-grade is that QA tests A-grade browsers rigorously. In nearly every case (approaching 100% for direct relatives of A-grade browsers, e.g. Firefox 3 on Linux), the end-user experience for A-grade and X-grade support under GBS is identical.

    About Chrome:

    Our data does not support your claim about its relative popularity. But that’s barely relevant because the true answer is the same as above: X-grade support does not equate exclusion.

    Why aren’t all great browser on the A-grade list? Because the list does not grade quality. It grades support. QA actively tests against A-grade browsers. That’s the difference. Even Chrome itself advises web developers that “If you’ve tested your website with Safari 3.1 then your site should already work well on Google Chrome.”

    Of course there are differences between browsers. Undoubtedly, Firefox/Linux differs from Firefox/Win differs from Flock/Win, even though they share the same internals. That’s why we test. But testing is expensive and so we use GBS to align our testing resources to (a) the technical landscape and (b) users’ actual behavior.

    To be crystal clear, Chrome’s home at Google is not a factor.

    I believe sentiments like those expressed in the comments above are the same sentiments that I myself hold dear: a desire that all users are supported (because at the end of the day we’re in the business of supporting users, not browsers!). That is precisely why I developed the GBS strategy; GBS clarifies that support is not binary, but graduated, and that it’s unwise to exclude. Yes, it’s difficult and imprecise deciding how to deploy QA resources — which is really what the A-grade label is. There are countless factors and endless data.

    I will continue to monitor the landscape carefully and welcome input and data from everyone.


  6. Thanks for the comments Nate, its good to know that YUI is tested on so many browsers.

    In fact, the testing that Yahoo performs on YUI is one of the main reasons why I use it.

  7. Nate,

    First, I’d like to say that your (and Yahoo’s) efforts are greatly appreciated. However, your reply to the concerns about Linux and Chrome basically amounted to a long-winded, rambling non-answer.

    Nobody asked about X-Grade support, nobody asked what A-Grade means in terms of Yahoo’s internal QA costs and mechanics, and nobody asked about the justification for ignoring those other more obscure browsers.

    Specifically, the real issue at stake is the reason why the relatively common Linux and Chrome, the latter of which is proven to be more popular than other platforms on your A-Grade list, have thus far been excluded from said list. In other words, what exactly are the secret criteria that cause Opera to gain more importance than Chrome (or Firefox on Linux) despite fewer people using it?


  8. Nate:

    That is a very valid response to David’s comment. Some don’t quite understand that “popular” is a relative term. In this case it is relative to the website in question (i.e. “”). However, you lost me when you said “Our data.” Would you mind publishing some of that data with a brief explanation of how you collected it? Most of us could use that same procedure for our own websites to determine where to allocate our QA resources!


  9. Thank you for the info posted from all. I really only want to know one thing: which non-microsoft browser is best supported by yahoo using a linux distro like open-suse or ubuntu? I really would like to get away from the expensive Microsoft product OS, its just too expensive anymore for me to operate MS. I have 5 PC’s and just the OS alone will rob my bank account. Please support the two main linux distros listed above.

  10. I’m shocked to see that FF3 on Win2k and Mac 10.4 would come down before IE6 on Win2k/XP. I know you’re all probably very aware of but we’re almost two versions down the road. Please help influence people to move off that browser by moving it off the A-grade list if a current version of FF is to be removed.