What is a Playwright trace?

A zip file that records a test run action by action: each click, fill and navigation with before/after DOM snapshots, a screencast, network requests and responses, console messages, and the test source. The trace viewer replays it as a timeline you can step through after the run.

Where does Playwright save traces?

The test runner writes `trace.zip` into the test's folder under `test-results/`. The HTML reporter copies it into `playwright-report/data/` and links it from the failing test. With the library API you choose the path in `context.tracing.stop({ path })`.

How do you open a Playwright trace?

Run `npx playwright show-trace trace.zip`, click Trace in a report served by `npx playwright show-report`, or drop the zip on trace.playwright.dev. All three are the same viewer, and all three need http(s) — the viewer will not start from file://.

Which trace mode should CI use?

`on-first-retry` with retries above 0 is the cheapest setup that still catches flakes; `retain-on-failure` keeps a trace for every failure at the cost of recording every test. `on` is for debugging sessions, not suites.

Do Playwright traces contain secrets?

They can. A trace stores network bodies and headers, cookies, DOM snapshots and typed text. A test that logs in with real credentials leaves those credentials in the zip. Use test accounts and treat traces as sensitive artifacts.

Playwright trace

A Playwright trace is a zip file that records a test action by action — every click, fill and navigation, with the page's DOM before and after it, a screencast, the network traffic, the console output and the line of test code that ran. The trace viewer replays it as a timeline after the fact, which is why it is the main evidence for a failure you cannot reproduce.

What is inside `trace.zip`

Part	What it holds
Actions	Each Playwright call, its arguments, duration and result
DOM snapshots	The page before, during and after each action — inspectable, not a picture
Screencast	Frames used for the filmstrip at the top of the viewer
Network	Requests and responses, including headers and bodies
Console	Page `console.*` output and errors
Sources	The test files, so each action maps back to a line

Snapshots are the part that makes traces useful: you can open the DOM at the moment an assertion failed and inspect the element that was there instead of the one the test expected.

Recording one

In the test runner, set the mode in the config:

// playwright.config.ts
use: {
  trace: "retain-on-failure",
},

or per run with npx playwright test --trace on. The modes are off, on, retain-on-failure, on-first-retry and on-all-retries. The generated config uses on-first-retry with retries: 0 outside CI — which is why a local failure often has no trace (fix).

With the library API:

await context.tracing.start({ screenshots: true, snapshots: true, sources: true });
// … actions …
await context.tracing.stop({ path: "trace.zip" });

Opening one

npx playwright show-trace trace.zip

Or drop the zip on trace.playwright.dev, a static build of the same viewer that reads the file in your browser. Both need a normal http(s) origin because the viewer runs on a service worker — it will not start from file:// or inside a sandboxed iframe with an opaque origin.

Why traces are sensitive

A trace is a recording of everything the browser saw. That includes response bodies, Cookie and Authorization headers, and text typed into password fields. Three rules:

Run suites against test accounts, never personal ones.
Store traces like any artifact that can hold credentials — not on a public bucket, not on a public link.
Prefer retain-on-failure over on, so passing tests do not leave recordings behind.

Traces and the HTML report

The HTML reporter links each test's trace from the report, copying the zips into playwright-report/data/. The report and the trace are two different things to share: the report is what reviewers read and argue about; the trace is what one person opens to work out why. Publishing the report to a stable link with the trace attached keeps both in one place — see share a Playwright report.

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