Browser Selection

The Runner leverages Playwright's multi-browser engine to execute tests against Chromium, Firefox, and WebKit from a single interface.

Supported Browsers

Browser	Engine	Default	Notes
Chromium	Blink	Yes	Matches Chrome 130+ and Edge behavior
Firefox	Gecko	No	Playwright patches for automation support
WebKit	WebKit	No	Safari engine, essential for iOS/macOS parity

Why Chromium Is Default

Chromium provides the fastest execution and broadest API compatibility. Switch to Firefox or WebKit when you need to verify cross-browser behavior or reproduce browser-specific bugs.

Selecting a Browser

Click the browser dropdown in the Runner toolbar before launching a run. The selected browser applies to the entire execution — all specs in the run use the same engine.

To run the same suite across multiple browsers, execute separate runs or use the CI Integration with a matrix strategy.

Playwright Device Descriptors

Beyond raw browser selection, xyva exposes Playwright's device descriptor library for emulating specific hardware:

Desktop Chrome      — 1920x1080, no touch, scale 1
iPad Pro 11         — 1194x834, touch enabled, scale 2
iPhone 14 Pro       — 393x852, touch enabled, scale 3, mobile UA
Pixel 7             — 412x915, touch enabled, scale 2.6

Device descriptors override viewport, user agent, hasTouch, and deviceScaleFactor. Select a device in Runner > Browser > Device or in the Device Lab.

Custom Viewports

If no preset fits your needs, enter a custom viewport width and height in the device configuration panel. Custom viewports use the selected browser engine without overriding the user agent.

Cross-Browser Differences to Watch

Common issues caught by multi-browser testing:

Issue	Chromium	Firefox	WebKit
date input rendering	Native picker	Native picker	Plain text fallback
dialog element	Supported	Supported	Partial support
CSS gap in flex	Full support	Full support	Older builds may fail
Clipboard API	Requires permission	Requires permission	Blocked in automation

Installing Browser Binaries

If a browser binary is missing, the Preflight Guard blocks the run and shows the install command:

npx playwright install chromium
npx playwright install firefox
npx playwright install webkit

Disk Space

Each browser binary is approximately 150-250 MB. Installing all three requires about 600 MB of disk space.