Playwright in headless/agent environment fails with 'browserType.launch: Executable doesn't exist' / browsers not installed. How do I fix it?

Cause: Installing the Playwright package does not necessarily download browsers, and each Playwright version needs its own matching browser binaries. The error appears when the binaries for the installed version are missing or Playwright is looking in a different location than where they were installed. Typical situations: the package was installed or upgraded but the browser install step was not run, a different user or container layer is running than the one that installed them, PLAYWRIGHT_BROWSERS_PATH differs between install and run, or a Docker image tag does not match the Playwright version. Fix (best first): 1. Install the browsers for the exact version in use: npx playwright install (or name one, for example npx playwright install chromium). Run it again after every Playwright upgrade. 2. On Linux and in fresh containers also install system libraries: npx playwright install --with-deps chromium, or npx playwright install-deps. Per the docs, behind a proxy on Linux run it as root so proxy variables reach the package manager. 3. If you set PLAYWRIGHT_BROWSERS_PATH to a custom folder, set it to the same value both when installing and when running. Setting it to 0 makes a hermetic install under node_modules/playwright-core/.local-browsers. Playwright removes browsers no longer used by any installed version; PLAYWRIGHT_SKIP_BROWSER_GC=1 or --no-remove prevents that. 4. In Docker either use the official image whose tag matches your Playwright version (the docs warn that a mismatch means Playwright cannot locate browser executables) or build from a Node image and run npx -y playwright@<your-version> install --with-deps. Use --init and, for Chromium, --ipc=host as recommended. 5. Make sure the process runs as the same user and home directory that ran the install; in agents and CI, put the install in the setup step before tests. 6. Check versions with npx playwright --version and keep the package version pinned. Don't: run browsers as root against untrusted sites; the Docker docs recommend a separate user and seccomp profile for that. Verify: npx playwright --version matches the installed package, and a minimal script that launches the browser and opens about:blank succeeds. Sources: https://playwright.dev/docs/browsers https://playwright.dev/docs/docker