Phones, tablets and browsers: what was measured

The research behind the mobile-web skill, the layout runner, export -Run for Web presets and doctor's Web and Android checks, gathered on 2026-10-21 with Godot 4.7.2 (mono and standard builds) on Linux. Android exports were built and inspected here; nothing ran on a phone (no device, and no KVM for an emulator), and iOS needs macOS.

Sources

Measured here

C# safe area

The SafeArea autoload in the skill, and the container that applies it (verified with the layout runner: the fixture's fixed menu passes on every profile only when SetInsets reaches it).

public partial class SafeMargins : MarginContainer   // anchor it full rect; children stay inside the safe area
{
    [Export] public int Extra { get; set; }
    private SafeArea _safeArea = null!;

    public override void _Ready()
    {
        _safeArea = GetNode<SafeArea>("/root/SafeArea");
        _safeArea.Changed += Apply;
        Apply();
    }

    public override void _ExitTree() => _safeArea.Changed -= Apply;

    private void Apply()
    {
        Rect2 view = GetViewportRect();
        Rect2 safe = _safeArea.CanvasRect();
        AddThemeConstantOverride("margin_left", Mathf.CeilToInt(safe.Position.X - view.Position.X) + Extra);
        AddThemeConstantOverride("margin_top", Mathf.CeilToInt(safe.Position.Y - view.Position.Y) + Extra);
        AddThemeConstantOverride("margin_right", Mathf.CeilToInt(view.End.X - safe.End.X) + Extra);
        AddThemeConstantOverride("margin_bottom", Mathf.CeilToInt(view.End.Y - safe.End.Y) + Extra);
    }
}

The autoload also connects GetTree().Root.SizeChanged to its Changed signal and reads --safe-area=L,T,R,B from OS.GetCmdlineUserArgs() in _Ready, so a desktop run can fake a notch.

Mistakes an agent is likely to make

1. Trying to export a C# game to the web, or "fixing" it with settings.
2. A threads build hosted on itch.io or GitHub Pages: a blank "missing features" page.
3. Exporting into the project, so the next export packs the last one.
4. Smoke-testing a release web build, which hides script errors.
5. Expecting ANDROID_HOME/JAVA_HOME to configure a headless export when editor settings exist.
6. Forgetting import_etc2_astc (the export refuses) and the icon.
7. C# on Android with the prebuilt template on net8.0; and the .NET first-run banner read as the target framework (DOTNET_NOLOGO=1).
8. A portrait game left in the default landscape orientation, or with an unswapped viewport.
9. Reading GetDisplaySafeArea() as canvas coordinates, or expecting it on web and desktop, or cutouts on iOS.
10. Treating ScreenGetDpi() on Android as exact, or the emulated mouse as multitouch.
11. Expecting low_processor_mode to help a game that redraws every frame.
12. Believing an automated browser proves the audio unlock.
13. Trusting Godot's exit code alone: 4.7.2 headless can abort with 134 after finishing. export runs a crashed export again, up to twice, after deleting what it left (exports[].retried); a crash on every run still fails.