v154 · css · covered on mdn
CSS text-decoration-inset
A CSS Text Decoration Level 4 property that controls how far underlines, overlines, and line-throughs are inset from — or, with negative values, extended beyond — the edges of the decorated text run. It accepts auto, lengths, and percentages, in one-value (both ends) or two-value (start, end) form, replacing background-gradient and extra-element workarounds for tuned decoration spacing and reveal effects.
The milestone=154 listing files this under “Enabled by default”, but as of 2026-09-20 the runtime flag record for CSSTextDecorationInset still reads status: "experimental" at trunk and the ChromeStatus record’s implementation status reads “Proposed” — so the property may not yet be on by default in your Chrome 154. To test regardless: enable chrome://flags/#enable-experimental-web-platform-features or launch with --enable-blink-features=CSSTextDecorationInset, and feature-detect with CSS.supports("text-decoration-inset", "0.1em") before relying on it.
this feature is documented on MDN
MDN’s reference covers the property in full — value syntax, formal definition and grammar, examples, specifications, and browser compatibility (verified substantive, 2026-09-20; the ChromeStatus record itself links this MDN page as the feature’s documentation). gendn doesn’t duplicate that here.
Why gendn doesn't duplicate MDN: this site exists for Chrome features that have no MDN reference yet. When MDN covers a feature completely, the honest page is a pointer to the canonical reference plus the shipping metadata MDN doesn't track — duplicated prose would only drift out of sync.
quick reference
| The change | New longhand property text-decoration-inset: auto | [ auto | <length-percentage> ]{1,2} — one value sets both the start and end offsets of underline/overline/line-through painting; two values set start and end independently (grammar per the css-text-decor-4 draft) |
|---|---|
| Chrome status | The milestone=154 listing files it under “Enabled by default” (fetched 2026-09-20; the listing is authoritative for filing). Disclosed: the runtime flag record for CSSTextDecorationInset still reads status: "experimental" at trunk and the detail record’s status text reads “Proposed”, so default-on in 154 stable is a target that may still be mid-flip. Implementation CL: 7748204 |
| Spec | CSS Text Decoration Module Level 4 — text-decoration-inset (Editor’s Draft) |
| MDN | text-decoration-inset (the ChromeStatus record links this same page) |
| Browser compatibility | BCD css/properties/text-decoration-inset.json (verified 2026-09-20): Chrome false — BCD has not yet recorded a Chrome shipping version (freshness gap vs the 154 listing; disclosed above). Firefox 146. Safari Technology Preview only. Edge mirrors Chrome |
| Baseline | No own web-feature entry: webstatus.dev returns 404 for text-decoration-inset (queried 2026-09-20); BCD tags it under the parent text-decoration web-feature. Not Baseline — Chrome is only now shipping and Safari is preview-only |
| ChromeStatus | 5178263526834176 — CSS text-decoration-inset (blink component Blink>CSS) |
| Interactive demos | Chrome Platform Showcase — CSS text-decoration-inset (route HEAD-checked 200, 2026-09-20) |
references
- Chrome Platform Status — CSS text-decoration-inset (API record)
- MDN — text-decoration-inset (canonical reference)
- CSS Text Decoration Level 4 — property definition
- Chromium CL 7748204 — implementation · runtime flag CSSTextDecorationInset
- BCD — css/properties/text-decoration-inset.json · webstatus.dev query (404 — no own entry)
- Chrome Platform Showcase — interactive demos