“Bulletproof” font fallbacks, and more changes to browser support

We’re making a few changes to our browser support that will improve the web font serving experience in a few new places. In this post, we’d like to walk you through those updates.

Introducing “bulletproof” CSS font fallbacks

We’re often asked why we use a JavaScript solution to serve fonts. One of the reasons is so we can quickly detect which font format is the most appropriate for a given browser. Usually a browser supports multiple formats, but the rendering of one format might be better compared to another. Browser detection lets us select the format that is the smallest, has the most features, and — most importantly — renders correctly.

But we cannot reliably detect every browser correctly. For that reason, today we are introducing a “bulletproof” @font-face fallback format in addition to our normal browser detection. This means that instead of serving no web fonts to unrecognized browsers, we serve a special CSS file that gives the browser several font formats. The browser can then select the most appropriate format. While this is less efficient than our default solution, it means improved web font support for lesser-known and unsupported browsers.

Dropping support for some browser versions

Going forward, we are no longer supporting the following browsers:

  • Chrome 4 and 5
  • Opera 10
  • Firefox 3.5

These browsers are no longer supported by their vendors, and all have very low usage. Fortunately, thanks to the new “bulletproof” @font-face fallback format, we will still be serving fonts to these browsers — so in practical terms nothing will change.

Now serving OpenType fonts for Android

We are also making some changes to our support for Android 3.1, 3.2, 4.0, and 4.1. We used to serve SVG fonts to these browsers, but going forward we will be serving OpenType fonts. This will improve text rendering and performance on those browsers. By using embedded OpenType fonts we also reduce the number of HTTP requests, resulting in a smaller and quicker font download.

Republish your kits

To see these changes on your websites, please republish your kit(s). This will ensure you’re using the latest versions of the fonts and the kit JavaScript. As always, please contact support@typekit.com if you have any questions, or other feedback.

4 Responses

  1. Sean McBride says:

    Yes! Excited to see these changes. Nice work!

  2. Craig Stump says:

    I have about 20 kits setup – is there a way to republish them all in one go automatically?

    Also, are you we going to see proper CSS file font serving anytime soon? The current method via JS isn’t great – websites don’t load if your servers are down, and the “alternate” method causes FOUC which is unacceptable. Obviously you’re using JS so you can track pageviews, but surely something can be done using fallbacks in the CSS @font-face (and tracking pageviews via CSS file requests)?

  3. yratof says:

    Same questions as Craig, If you’ve got 20-30 sites, is there a mass publish button?

  4. Ivan says:


    In case you do not mind using command-line tools, try this one for mass publishing:



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