Browser setup

Playwright Core comes with Dyno. Download a browser once, then run your tests:

npx dyno install                      # Chromium, the default
npx dyno --ui
npx dyno install --browser firefox
npx dyno --browser firefox --ui
npx dyno install --browser webkit
npx dyno --browser webkit

Runs never download browsers. On Linux, dyno install --with-deps also installs system dependencies and may need administrator access. Use dyno browsers to see downloaded builds and paths.

Headless Chromium uses Playwright’s default headless shell. On macOS, Chromium --ui, Chrome, Edge and custom Chromium executables reject captures taller than 16,384 physical pixels. Full Chromium can repeat content beyond that height while reporting valid dimensions. Use default headless Chromium for long-page images. This is a conservative support limit; some custom builds may work beyond it.

Choose a browser

Browser	How to run
Chromium, Firefox, WebKit	Install its matching build, then use --browser
Installed Chrome or Edge	dyno --browser chrome or --browser edge
Stock Safari, other browsers and devices	dyno --manual, then open the printed URL

WebKit isn’t Safari; passing WebKit tests doesn’t establish Safari behavior. Chrome and Edge availability is checked at launch. Managed runs support screenshots and viewport sizing, with a private context per worker. Tests and Interactor still run in the browser.

Open the URL yourself

Manual runs need no local browser installed. Open the printed URL and click Start tests if the popup was blocked. Keep the app and companion windows open. Use --manual --host 0.0.0.0 to reach Dyno from another device.

A URL-only browser can’t take screenshots or resize its tab. Required captures fail; explicitly optional ones report a skipped image. Viewport requests and fixed config dimensions must match the actual window. See viewport sizing.

Native capabilities

Use app.native.capabilities to choose browser-specific coverage explicitly. Required operations fail when unsupported; Dyno doesn’t substitute a synthetic event.

Feature	Chromium / Chrome / Edge	Firefox	WebKit	Manual URL
Native keys and pointer	Yes	Yes	Yes	Unavailable
App HTTP request guard	Yes	Yes	Yes	Unavailable
Dialogs and browser console	Yes	Yes	Yes	Unavailable
Color scheme and reduced motion	Yes	Yes	Yes	Unavailable
Clipboard permission grants	Read/write	Unavailable	Read only	Unavailable
Virtual authenticator	Yes	Unavailable	Unavailable	Unavailable
App network offline	Yes	Unavailable	Unavailable	Unavailable

Native state resets between tests. Cookies, storage, and backend cleanup remain your project’s responsibility. Chromium offline keeps companion HTTP connected, but can change its navigator.onLine too.

Set browser.locale and browser.timezoneId when creating managed contexts. browser.deviceScaleFactor accepts finite values from 1 to 3, including fractional ratios. Set browser.hasTouch for touch input, browser.isMobile for mobile viewport behavior, and browser.userAgent when needed. Firefox does not support isMobile. These are browser context settings; they do not reproduce a phone’s OS or hardware.

Custom executables

Prefer Playwright’s matching builds. Use --browser-path or browser.path for a compatible executable; Dyno passes it to Playwright without scanning application folders. Extra browser.args can break automation. Profile and instance flags are reserved because Dyno owns the session.

Known limits

Chromium full-page and element captures briefly pause app JavaScript to avoid an internal browser resize. Queued callbacks resume afterward. Resume an existing app debugger pause before capturing; Dyno won’t resume it for you.

CI exercises Chromium, Firefox, and WebKit on Linux and macOS. Windows, phones, iOS, and TVs still need verification. Manual browsers need modern APIs, and their popup and background-tab policies can affect the runner.

For launch failures, check dyno browsers, then run dyno doctor with that browser. Include its diagnostic when reporting a problem. A failed launch is an error; Dyno never silently switches browsers.