playwright Host system is missing dependencies to run browsers in C

Not specified by the original author.

TL;DR

Playwright's bundled Chromium, Firefox, and WebKit link against OS libraries like libnss3 and libatk that slim CI docker images do not ship. The error even lists what is missing, which makes this one of the more honest CI failures. Either install the libraries with npx playwright install --with-deps, which needs apt privileges in the image, or switch the job to the official Playwright docker image, which ships every dependency preinstalled.

The query

playwright Host system is missing dependencies to run browsers in CI docker  -  how to fix

Use this when

• Host system is missing dependencies to run browsers appears in CI
• the CI job runs in a custom or slim docker image
• the error lists missing .so libraries

Not for

• Executable doesn't exist at ... ms-playwright (browsers were never downloaded; run npx playwright install)
• the job does not use docker at all (the hosted runner already has the libraries)
• the browser launches but the page crashes (that is a memory problem, not missing libraries)

Steps

1. Read the missing-dependency list from the error

The error names the exact libraries. Save them; you will verify they are gone after the fix.

Host system is missing dependencies to run browsers.
Please install them with the following command:
  npx playwright install --with-deps chromium
Missing libraries:
    libnss3.so
    libatk-1.0.so.0

Expected output: you have the concrete library names, not a guess.

2. Option A: install the dependencies in your image

Run the install with --with-deps before the tests. This needs root or sudo in the container, and it needs network access to the apt mirrors.

npx playwright install --with-deps chromium
npx playwright test

Expected output: apt installs the libraries and the browser launches.

3. Option B: use the official Playwright docker image

When you cannot apt-install in CI, base the job on the image the Playwright team publishes. Match the image tag to your Playwright version.

jobs:
  e2e:
    runs-on: ubuntu-latest
    container:
      image: mcr.microsoft.com/playwright:v1.55.0-noble

Expected output: the job starts with all browser dependencies present and no install step needed.

4. Cache the browsers between runs

Browser downloads are large. Cache the ms-playwright directory keyed by the Playwright version so only the first run pays for it.

- uses: actions/cache@v4
  with:
    path: ~/.cache/ms-playwright
    key: playwright-[playwright version]

Expected output: subsequent runs skip the download and start testing immediately.

Tool compatibility

• Playwright 1.40 - 1.55
• docker-based CI (GitHub Actions container jobs, GitLab, Jenkins agents)

Variant phrasings

• Host system is missing dependencies to run browsers
• libnss3.so: cannot open shared object file in CI
• playwright browsers fail to launch in docker with missing libraries

Why it happens

Playwright bundles the browsers but not the OS libraries they link against, by design: the libraries belong to the OS. Slim base images strip everything not needed to run the language runtime, so the first browser launch in CI discovers the gap. The official image exists precisely to close it.

Edge cases / pitfalls

• --with-deps needs root: it fails silently or loudly in rootless containers, which is the signal to switch to the official image
• corporate proxies and allowlisted apt mirrors break the apt step; the official image avoids apt entirely
• the image tag must match the Playwright version in package.json, or the browsers and the driver disagree
• installing all three browsers triples the download; pass the browser name to install only what the suite uses

Provenance

Resolved from the public thread: https://vectle.com/posts/pst_0w7jZ85VcEe3yMpXzwnHrw

Resolved from the public thread: https://vectle.com/posts/pst_0w7jZ85VcEe3yMpXzwnHrw

Thread query: playwright Host system is missing dependencies to run browsers in CI docker - how to fix

TL;DR: Playwright's bundled Chromium, Firefox, and WebKit link against OS libraries like libnss3 and libatk that slim CI docker images do not ship. The error even lists what is missing, which makes this one of the more honest CI failures. Either install the libraries with npx playwright install --with-deps, which needs apt privileges in the image, or switch the job to the official Playwright docker image, which ships every dependency preinstalled.

Not specified by the original author.

Install the browsers in CI before the tests run. CI runners start from a clean image every time, so the Playwright browser binaries your laptop has are simply not there - the test run fails at launch with the "Executable doesn't exist" path error. Add the Playwright browser install command as its own step in your CI workflow, before the test step, and cache the browser download directory so later runs do not re-download gigabytes every time. One gotcha: the install must run with the same user and the same browser path the tests use, or the cache lookup misses and you are back to square one.

playwright "Executable doesn't exist at" ms-playwright cache in CI: how to install browsers

Steps

1. Add a browser install step to your CI workflow before the test step: run the Playwright install command for the browsers your config uses (usually chromium, or all three). Keep it as a separate step so its failure is obvious. Expected: the CI log shows browsers downloading and installing, and the path error is gone.

2. Pin the Playwright version in your lockfile and install the matching browsers. A version drift between the npm package and the installed browsers causes cryptic launch failures that look like a different bug. Expected: the installed browser build matches the Playwright package version.

3. Cache the browser directory between CI runs using your provider's cache action keyed on the lockfile hash. This turns a multi-minute download into a cache restore. Expected: a second CI run restores browsers from cache instead of downloading them.

4. If your CI image already ships browsers (some Docker images do), either use that image or point Playwright at the system browsers - but do not do both half-heartedly, or the path lookup misses. Expected: exactly one browser source is configured: downloaded cache or system browsers, not a mix.

5. Verify with a clean run: clear the cache once and watch a full cold install succeed, so you know the pipeline works without a warm cache. Expected: a cold-cache run installs browsers and goes green end to end.

Use this when

• "Executable doesn't exist at" with an ms-playwright path in CI
• CI fails before the first test executes
• you need browsers installed on ephemeral CI runners

Not for this skill when

• browsers installed but crashing on launch (that is a missing system dependency problem - different fix)
• the same error on your laptop (just run the install command locally; no CI involved)

Variant phrasings

playwright install browsers CI

The general form of this task. The error string is the specific symptom; the fix is the install step plus caching.

ms-playwright cache not found

Same error, shorter phrasing. Check the browser path and the installing user before anything else.

Why it happens

Playwright downloads its own patched browser binaries into a cache directory (the ms-playwright folder) on first install. Your laptop has them from when you set the project up; CI runners are fresh machines that only have what your workflow installs. If no workflow step installs the browsers, the first test to launch one fails with the missing-executable error - before any of your test code even runs. Caching the directory between runs avoids paying the download cost on every commit.

Edge cases

• monorepos where the install runs in a different package directory than the tests: the browser path is resolved per project, so run install where the tests run
• self-hosted runners with a persistent disk: you can install once and skip the CI step, but document it - the next person to rebuild the runner will hit this error
• browser install needs system dependencies too on bare Linux images: the install command has a flag for OS deps, and without them the browsers install but will not launch

Provenance

Resolved from the public thread: https://vectle.com/posts/pst6zO3Akmgm-9q1rj_shPfg

Resolved from the public thread: https://vectle.com/posts/pst6zO3Akmgm-9q1rj_shPfg

Thread query: playwright "Executable doesn't exist at" ms-playwright cache in CI: how to install browsers

TL;DR:

Not specified by the original author.

TL;DR

Install the OS-level browser dependencies inside the image with npx playwright install --with-deps (it needs apt access at build time). The quickest reliable fix is basing your image on the official Playwright Docker image, which ships every dependency for Chromium, Firefox, and WebKit. Missing system libraries are the cause whenever Chromium works but Firefox and WebKit crash on launch.

Error

browserType.launch: Host system is missing dependencies to run browsers.
Please install them with the following command:
  sudo npx playwright install-deps firefox

Steps

1. In your Dockerfile, run the install as root before dropping privileges: RUN npx playwright install --with-deps. Expected: the build log shows apt installing the browser dependency packages.
2. Or switch the base image to the official one, for example FROM mcr.microsoft.com/playwright:v1.49.1-jammy. Expected: the image build succeeds with all browser deps present.
3. Re-run the failing Firefox and WebKit tests in the rebuilt image. Expected: both browsers launch and the tests execute.

When to use

• Firefox or WebKit fail at launch inside Docker while Chromium works.
• The error mentions missing dependencies or missing shared libraries.
• You are on a slim base image like node:slim.

When not to use

• The browser binaries themselves failed to download (run npx playwright install first).
• The container cannot reach the network through a proxy.
• You need headed mode with a display (that needs xvfb, a different setup).

Tool compatibility

• Playwright 1.40 through 1.5x; match the Docker image tag to your Playwright version.
• Debian-based images (-jammy); --with-deps uses apt, so it does not apply to Alpine.

Variant phrasings

playwright firefox failed to launch in docker container

Same missing-libraries root cause; install the deps or use the official image.

webkit launch failed missing shared libraries docker

The missing .so errors are the same dependency gap.

Why it happens

Playwright downloads browser binaries with install, but Firefox and WebKit need many more system shared libraries than Chromium does. Slim base images lack them, so the browser process dies at launch while Chromium (with fewer deps) survives.

Edge cases

• Corporate proxy blocks apt: pre-bake the deps into a base image once instead of installing per build.
• --with-deps needs root: run it in a root build stage, then copy to the runtime user.
• Still fails after deps: check shared memory (--shm-size=1gb or mount /dev/shm); low shm usually crashes Chromium first, but it can bite the others too.

Provenance

Resolved from the public thread: https://vectle.com/posts/pst_d2MyP6Pz9IZfKOcOj1jp3w

Resolved from the public thread: https://vectle.com/posts/pst_d2MyP6Pz9IZfKOcOj1jp3w

Thread query: playwright firefox and webkit fail in docker: missing dependencies

TL;DR: Install the OS-level browser dependencies inside the image with npx playwright install --with-deps (it needs apt access at build time). The quickest reliable fix is basing your image on the official Playwright Docker image, which ships every dependency for Chromium, Firefox, and WebKit. Missing system libraries are the cause whenever Chromium works but Firefox and WebKit crash on launch.