Test Runners

Test Suites Overview

Capture flakes in CI. Investigate failures with browser DevTools. And achieve a 99.9% pass rate.

Test Suites Overview

Using Replay with your test suite

Replay is a drop-in replacement for the browser you currently use when running your end-to-end tests. Whether you use Playwright, Cypress, or other test runners, you simply swap your current browser with Replay Browser and that’s it.

Explained in simplest possible terms, this is how your test script looks when Replay is integrated:


npx playwright test --project replay-chromium


npx cypress run --browser replay-chromium

Difference when using Replay Browser

Under the hood, Replay Browser is just Chromium browser, just like Google Chrome, or Microsoft Edge. But as you run your tests, Replay Browser creates a recording of your runtime.

At the first glance, that recording may look like a series of snapshots of your application, but you’ll learn that a replay is actually a very different concept. In fact, there are zero snapshots created during recording, which results in a minimal overhead as you run your tests. And yet, the information gathered is infinitely more robust.

When to use Replay with your tests

There are a couple of strategies you can adopt, but generally you can use Replay Browser with every test run on your CI, as there is both short-term and long-term value.

When a test fails on CI, you don’t need to replicate it locally anymore. A recording captures your test run exactly as it happened and will provide you better insight than if you tried to locally reproduce an issue from CI.

If you battle with flaky tests, you can compare a failing and a passing test to detect the difference. This can be caused by inconsistent data, race condition, test running too fast, or any other reason. What’s important is that the reason will no longer be a mystery, because Replay Browser records your test steps, your app, and everything in between. If you were able to capture the test flake, you’ll be able to debug it. Soon, we’ll be able to help you find the root cause.

Test Steps Trace

Replay Devtools work great with your existing test suite. Cypress and Playwright plugins allow you to rewind or fast forward to any command from your test run.

The command details panel contains information on passed arguments, returned values and targeted element. Commands are integrated with the rest of DevTools. This means you can jump from a command detail into Elements panel, or inspect API calls in the Network panel.

Playwright panel

Jump To Code

See what actually happened when your test clicked, typed or in other way interacted with your website. Jump from a test command right into the function that was called on interaction.

With information on line hit counts and jumping through line executions you’ll be able to narrow down a flake root cause in minutes.

Jumping to code

Visualize Your Race Conditions

Flakiness can be a caused by a single line of code. Reveal that line with a print statement. Find race conditions, unexpected data, rendering issues - you name it.

We have stories of 2 pixel shifts and false positives that caused headaches to test maintainers. Learn more about the power of time-traveling console logs.

Race condition

Test Suite Analytics

Test Suite Dashboard helps you stay on top of your test suite health. Focus on your top failing, or most flaky tests. Get insights from your newest feature branch. Focus on most common errors.

Analytics give you actionable insights into your test runs and help you focus on the most important tests.

Test suite analytics

Debug CI Runs With Ease

What happens on CI no longer stays on CI. Replay Browser captures your test runs exactly as they happened and brings them to Replay DevTools where you can inspect them.

You can zoom out to take a look at your whole test run, or filter out those that are failing the most.

Continuous integration

Integrate With Any Framework

If test flakiness pushed you to consider switching to a new testing framework, be at ease. Replay is a browser based on Chromium that can be integrated to any test framework.

We have created an extra tooling around the most popular ones today - Cypress.io and Playwright.