Incremental Font Transfer

[wmedrano]

Specification

https://www.w3.org/TR/IFT/

Description

Incremental font transfer enables the browser to download only the specific portions of a web font needed to render the text currently visible on a page. This reduces bandwidth usage and improves page load times for sites using large fonts. This allows developers to optimize web performance without needing to manually generate and manage font subsets.

Documentation

In progress https://chromestatus.com/feature/5135917565214720

Browser support

Chromium in progress https://chromestatus.com/feature/5135917565214720

[ddbeck]

Thanks for filing this issue, @wmedrano. I'm taking some notes here mostly for myself (or someone else) who might want to create a feature entry, so a review of the following is optional but welcome.

ID is likely to be incremental-font-transfer (or maybe just incremental-fonts).

Likely description, in our style:

The tech(incremental) keyword for the @font-face CSS at-rule src descriptor loads only those portions of a font needed for the text visible on a page. You can use this to reduce bandwidth usage and page load times caused by fonts with many glyphs, instead of manual font subsetting.

(Perhaps we should mention something about the font format being special, here? Not sure if we need to get into that much detail. Maybe we can just say, "an eligible font.")

No one appears to be shipping this yet, so I'm tagging this as an early feature. More support links:

• Incremental Font Transfer mozilla/standards-positions#872
• Firefox bug 1977870
• Incremental Font Transfer WebKit/standards-positions#461
• WebKit bug 296310
• Add Incremental Font Transfer Fyrd/caniuse#6279