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@ddbeck ddbeck commented Jan 20, 2026

Summary

The display-mode CSS media query has several values (e.g., display-mode: browser, display-mode: fullscreen). Support for those values specifically was previously locked in notes; this PR busts them out.

Test results and supporting details

For the most part, I trusted these web platform tests to determine if a browser is aware of a value (i.e., to determine if (display-mode: made-up-example) is functionally equivalent to not all):

For non-partial "is always true" notes, I mostly used the existing BCD on the display manifest member to determine what to expect (e.g., if a browser doesn't implement minimal-ui, then display-mode: minimal-ui is always false, even though it may be a valid media query).

For the remaining notes and partials, I relied on bugs and prior discussion on this repo. In some cases (e.g., WebKit bug 216395), I used the information in a bug to make a determination, but did not actually treat it as a bug (e.g., Safari shouldn't, by specification, compute display-mode: fullscreen to true for a fullscreen window with tabs UI).

Some of this is very difficult to test (e.g., some behavior is specific to installed PWAs), so I didn't test this comprehensively. I suspect some of this is a little wonky or off, but it's more explicit now and will be easier to maintain in the future.

Related issues

@github-actions github-actions bot added data:css Compat data for CSS features. https://developer.mozilla.org/docs/Web/CSS size:l [PR only] 101-1000 LoC changed labels Jan 20, 2026
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github-actions bot commented Jan 20, 2026

Tip: Review these changes grouped by change (recommended for most PRs), or grouped by feature (for large PRs).

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LGTM, double-checked as much as I could, and most is plausible, even if we don't seem to have a bug for Firefox Android 116 adding support for minimal-ui/standalone (but this is pre-existing data).

@caugner caugner merged commit a1518fe into mdn:main Jan 23, 2026
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@mdn-bot mdn-bot mentioned this pull request Jan 23, 2026
@ddbeck ddbeck deleted the break-out-display-mode branch January 29, 2026 14:36
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data:css Compat data for CSS features. https://developer.mozilla.org/docs/Web/CSS size:l [PR only] 101-1000 LoC changed

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css.at-rules.media.display-mode - "fullscreen" keyword doesn't work in Opera PC css.at-rules.media.display-mode - Incomplete Safari Support

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