Bug(android): SystemBars breaks edge-to-edge and does not expose top inset on Android WebView < 140 #8651

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1. adrianofalleti98

   added

   triage

   on Oct 12, 2026
2. adrianofalleti98

   added the

   Bug

   issue type on Oct 12, 2026
3. eric-horodyski

   assigned

   theproducer

   on Oct 22, 2026
4. dpa99c commented on Oct 29, 2026

   

   dpa99c

   on Oct 29, 2026

   More actions

   Additional data from the other side of the threshold: in our app the passthrough path is also broken on Android System WebView 140–143. env(safe-area-inset-*) is 0px up to and including 143.0.7499.3, and correct from 144.0.7559.133.

   Environment

   - @capacitor/android 8.3.1 (@capacitor/core, @capacitor/cli 8.5.0)
   - minSdkVersion 30, compileSdkVersion 37, targetSdkVersion 37
   - androidx.activity 1.11.0
   - EdgeToEdge.enable(...) called in MainActivity.onCreate(), before super.onCreate()
   - <meta name="viewport" content="..., viewport-fit=cover">
   - SystemBars insetsHandling: default ("css")
   - Pixel 9 Pro emulator, Android 16 (API 36)
       - WebView changed by installing Android System WebView APKs on the same image

   The WEBVIEW_VERSION_WITH_SAFE_AREA_FIX check is the same in 8.5.3 (as quoted above), so this should still apply on the latest version.

   Results

   Same emulator and same app build; only the WebView version changes. Every row takes the passthrough path (getWebViewMajorVersion() >= 140).

   Android	API	WebView	env(safe-area-inset-top)	env(safe-area-inset-bottom)	Result
   16	36	143.0.7499.3	0px	0px	❌ content under status bar and navigation bar
   16	36	144.0.7559.133	52px	24px	✅
   16	36	145.0.7632.45	52px	24px	✅
   16	36	146.0.7680.178	52px	24px	✅
   16	36	148.0.7778.217	52px	24px	✅

   Values were read with getComputedStyle(document.documentElement).getPropertyValue(...) on custom properties defined as env(safe-area-inset-top, 0px) / env(safe-area-inset-bottom, 0px).

   On 143.0.7499.3 the WebView is full screen, so Capacitor has removed the padding but the page gets no insets:

   innerHeight
   > 952
   screen.height
   > 952
   visualViewport.height
   > 952
   visualViewport.offsetTop
   > 0

   The same symptom appears on a physical Galaxy S26 (Android 16, launch firmware, WebView 140.0.7339.207); env() was not measured there. Physical devices on WebView 157/158 (Android 11, 14 and 17) render correctly.

   Note: I can't report Capacitor's injected --safe-area-inset-top/-bottom for these runs, because our app overwrites those two variables from env(). The injected --safe-area-inset-left/-right were present inline, so injectSafeAreaCSS() did run. Apps that use only the injected variables may therefore not see this on API 35+. On API ≤ 34 nothing is injected (Build.VERSION.SDK_INT >= VANILLA_ICE_CREAM check), so env() is the only source there.

   Cause

   This matches the inset change documented by Chromium in Android WebView & Insets:

   In M136, WebView added support for displayCutout() insets and systemBars() insets. These were forwarded to the web content via the safe-area-insets CSS values. Due to compatibility issues, we only supported passing these inset values to the web content when the WebView was fullscreen.

   In M144, we expanded inset support to all WebViews regardless of whether they are displaying fullscreen or not.

   So on 140–143, whether env(safe-area-inset-*) is populated depends on WebView's own fullscreen check. Our WebView fills the window (see above) but evidently doesn't pass that check; I haven't dug into why. Apps that do pass it would get correct values from 140, which may be why 140 looked like the right threshold. From 144 the check no longer applies, which matches the boundary in the table.

   Possible fix

   Raise WEBVIEW_VERSION_WITH_SAFE_AREA_FIX from 140 to 144, the version from which Chromium forwards the insets to all WebViews. On 140–143 this puts the WebView on the padding path, which lays out correctly on those versions.

   -    private static final int WEBVIEW_VERSION_WITH_SAFE_AREA_FIX = 140;
   +    private static final int WEBVIEW_VERSION_WITH_SAFE_AREA_FIX = 144;

   On the fix proposed above (passthrough based only on viewport-fit=cover): on 140–143 it would depend on the injected CSS variables, as on < 140. In 8.3.1 those are injected only on API 35+. I haven't checked whether 8.5.x changed that.

   For reference, we've worked around it in the app by padding android.R.id.content with the systemBars() | displayCutout() insets and passing cleared insets on (insets.inset(...), not CONSUMED), with insetsHandling: "disable". With that, layout no longer depends on the WebView version.