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[css-env-1] Update env(preferred-text-scale) explainer for <meta> and WebView #12464

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davidsgrogan merged 3 commits into from
Jul 11, 2025
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[css-env-1] Update env(preferred-text-scale) explainer for <meta> and WebView #12464

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[css-env-1] Update env(preferred-text-scale) explainer for <meta> and…
davidsgrogan Jul 8, 2025
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Update css-env-1/explainers/env-preferred-text-scale.md
davidsgrogan Jul 11, 2025
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Update css-env-1/explainers/env-preferred-text-scale.md
davidsgrogan Jul 11, 2025
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7 changes: 7 additions & 0 deletions css-env-1/explainers/env-preferred-text-scale.md
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Expand Up @@ -383,7 +383,11 @@ If an author didn’t want headings – for example – to scale up at the same

By default, [Android Webview scales the text size by the system font scale factor](https://crsrc.org/c/android_webview/java/src/org/chromium/android_webview/AwSettings.java;l=382-385;drc=fbd39d07c1deaf2ec4a8ea32260503369d10bdbb). App developers may override this default by invoking [setTextZoom()](<https://developer.android.com/reference/android/webkit/WebSettings#setTextZoom(int)>).

**Update 2025-Jul-08:** The interaction between WebView and env() is in flux. See the [discussion on blink-dev.](https://groups.google.com/a/chromium.org/g/blink-dev/c/bZuQAcwcEig/m/6F5w5S97AQAJ)

<del>
We recommend that apps embedding pages that use `env(preferred-text-scale)` override Android Webview’s default scaling with `setTextZoom(100)`. But `text-size-adjust` doesn’t work in Android Webview yet. See [https://crbug.com/419469463](https://crbug.com/419469463)
</del>

### Example use cases

Expand Down Expand Up @@ -434,6 +438,9 @@ The minimum font size setting is not involved in the derivation of `env(preferre

### New meta viewport key for changing text-scale

**Update 2025-Jul-08:** The `<meta>` approach has evolved since this document was written.
See the [Meta tag for text scaling behavior Explainer](https://github.com/w3c/csswg-drafts/blob/main/css-env-1/explainers/meta-text-scale.md)

```html
<meta
name="viewport"
Expand Down