WebView API Compatibility Check

This example application tests and reports which Web APIs are available in the current WebView engine.

Purpose

Different platforms use different WebView engines:

Linux GTK4: WebKitGTK 6.0 (WebKit-based)
Linux GTK3: WebKit2GTK 4.1 (WebKit-based)
Windows: WebView2 (Chromium-based)
macOS: WKWebView (WebKit-based)

Each engine supports different Web APIs. This tool helps you understand what APIs are available for your Wails application on each platform.

Building

bash

# Linux GTK4 (default)
go build -o webview-api-check .

# Linux GTK3 (legacy, opt-in)
go build -tags gtk3 -o webview-api-check .

# Windows/macOS
go build -o webview-api-check .

Usage

Run the application
Click "Run API Tests" to test all Web APIs
View results organized by category
Use filters to find specific APIs
Export report as JSON for comparison

API Categories Tested

Category	APIs Tested
Storage	localStorage, IndexedDB, Cache API, File System Access
Network	Fetch, WebSocket, EventSource, WebTransport
Media	Web Audio, MediaRecorder, MediaDevices, Speech
Graphics	Canvas, WebGL, WebGL2, WebGPU
Device	Geolocation, Sensors, Battery, Bluetooth, USB
Workers	Web Workers, Service Workers, Shared Workers
Performance	Observers, Timing APIs
Security	Web Crypto, Credentials, WebAuthn
UI & DOM	Custom Elements, Shadow DOM, Pointer Events
CSS	CSSOM, Container Queries, Modern Selectors
JavaScript	ES Modules, BigInt, Private Fields, etc.

Understanding Results

Supported (green): API is fully available
Partial (yellow): API exists but may have limitations
Unsupported (red): API is not available

Some APIs are marked with notes:

"Chromium only" - Available in WebView2 but not WebKit
"Experimental" - May not be stable
"Requires secure context" - Needs HTTPS
"PWA context" - Only available in installed PWAs

Comparing Platforms

Run the app on different platforms and export JSON reports. Compare them to understand API availability differences:

bash

# On Linux GTK4
./webview-api-check
# Export: webview-api-report-linux-20240115-143052.json

# On Windows
./webview-api-check.exe
# Export: webview-api-report-windows-20240115-143052.json

Known Differences

WebKitGTK vs WebView2 (Chromium)

WebView2 (Windows) typically supports more APIs because Chromium is updated more frequently:

File System Access API (Chromium only)
Web Serial, WebHID, WebUSB (Chromium only)
Various experimental features

WebKitGTK may have better support for:

Standard DOM APIs
CSS features (varies by version)

GTK3 vs GTK4 WebKitGTK

GTK4 uses WebKitGTK 6.0, GTK3 uses WebKit2GTK 4.1. The WebKit version determines API support, not GTK version.