Intent to Ship: CSS letter-spacing and word-spacing: percentage values

[Minseong Kim]

Contact emails

jja0...@gmail.com

Specification

https://www.w3.org/TR/css-text-4/#propdef-letter-spacing

https://www.w3.org/TR/css-text-4/#propdef-word-spacing

Summary

Enables percentage values for the letter-spacing and word-spacing CSS property, as defined in the CSS Text Module Level 4 spec. Percentage values are calculated relative to the advance measure of the space character (U+0020). This gives developers more robust and flexible control over typography, particularly in responsive designs where text spacing needs to adapt to different viewports and font sizes.

Blink component

Blink>Layout>Inline

Web Feature ID

letter-spacing

Search tags

letter-spacing, word-spacing

Risks

Interoperability and Compatibility

Risks are low. This is a support for new value of CSS properties. So sites not using properties won't be affected. Firefox and Safari has supported this feature for years.

Gecko: Shipped/Shipping Firefox is failing so many letter-spacing tests: https://wpt.fyi/results/css/css-text/letter-spacing?label=experimental&label=master&aligned. But those are related the line ending or boundary handling of letter-spacing, not the percentage values. Related discussion: https://github.com/w3c/csswg-drafts/issues/1518

WebKit: Shipped/Shipping (https://github.com/WebKit/WebKit/pull/18771)

Web developers: No signals (https://issues.chromium.org/issues/327740939) The issue has 3 votes.

Other signals:

WebView application risks

Does this intent deprecate or change behavior of existing APIs, such that it has potentially high risk for Android WebView-based applications?

No information provided

Debuggability

No information provided

Will this feature be supported on all six Blink platforms (Windows, Mac, Linux, ChromeOS, Android, and Android WebView)?

Yes

Is this feature fully tested by web-platform-tests?

Yes
- "letter-spacing-percentage-001.html" file in https://wpt.fyi/results/css/css-text/letter-spacing - "word-spacing-percentage-001.html" file in https://wpt.fyi/results/css/css-text/word-spacing

Tracking bug

https://issues.chromium.org/issues/327740939

Estimated milestones

Shipping on desktop	145
Shipping on Android	145
Shipping on WebView	145
Shipping on iOS	145

Link to entry on the Chrome Platform Status

https://chromestatus.com/feature/5074916059381760

This intent message was generated by Chrome Platform Status.