Reconsider WOFF2

[mathiasbynens]

Reconsider WOFF2

[mmastrac]

Still waiting on Safari and for WOFF2 to make it into the stable channels of every browser unfortunately. I would wager within a year this can flip. Leaving open as a tracking bug.

[konklone]

@mmastrac If WOFF2 were listed as an option in the resulting .css file, would browsers which don't support it try and fail to use it, and have broken fonts? Is there any downside to including WOFF2 in the file for browsers that don't support it?

[mmastrac]

Oh crap -- I think I just realized the confusion. The WOFF2 support page is here: http://caniuse.com/#feat=woff2 (I linked to WOFF by accident)

I'll fix the link on the front page. Does this make sense?

[mathiasbynens]

@konklone

If WOFF2 were listed as an option in the resulting .css file, would browsers which don't support it try and fail to use it, and have broken fonts?

No. (But as webfont-dl inlines the font as a base64-encoded data URL by default, it would increase the resulting file size.)

Is there any downside to including WOFF2 in the file for browsers that don't support it?

No.

TL;DR Everything is awesome!

[mmastrac]

The downside is basically size, which is somewhat antithetical to the reasons you'd use WOFF2: the byte savings over WOFF.

If you're including WOFF+WOFF2, that'll be on average ~170% of the size of a WOFF-only CSS file (I'd say this is probably something to avoid).

If you inline WOFF2 and link WOFF, cutting edge browsers will potentially save 30-50% on the CSS download, but modern browsers that don't speak WOFF2 yet (Safari, IE) will pay a reasonably large penalty having downloaded the CSS, ignored the WOFF2 and moved on to WOFF.

I'd say that if you can guarantee that most of your users are on Chrome and Firefox 39+ (currently not actually the stable version), then enabling WOFF2 is probably a win. If not, I'd suggest sticking with the default.

[mmastrac]

I'm quickly revisiting this since the web is moving quickly these days -- http://caniuse.com/#feat=woff2 suggests that WOFF2 is 50%+ of the global market share which means that it might be worth adding a non-default flag to enable this profile.

Adding help wanted.

[mmastrac]

woff2 support is now at 80% - when I get a chance I'll make this the default.

[mmastrac]

Committed