Browser Checks
Browser Checks run a Playwright script in headless Chromium on a schedule. The check fails when an assertion breaks or the global timeout fires, and every run keeps logs, screenshots, video, and a Playwright trace for replay.
Use a Browser Check when the failure mode is in the rendered page, not the HTTP response. Login flows, search results, multi-step checkouts, and broken JavaScript all return 200 to a plain GET but break for real users.
Create a browser check
Runtime 2026.05
The 2026.05 runtime is the default for new browser checks. It runs on Node 24 with Playwright 1.59.1 and adds three capabilities on top of the script API.
What 2026.05 adds 3 features
Web VitalsLCP / CLS / TBT / FCP / TTFBStep reportingtest.step()test.step('...') call shows up in the run view with a green or red status and its own duration. A failed multi-step check points at the exact stage that broke instead of dropping a wall of logs on the on-call engineer.Trace and videoretain-on-failureWeb Vitals
The runtime injects a PerformanceObserver into every page your script opens. After each navigation it captures the five Core Web Vitals and stores them on the run, so you can watch them trend without writing any custom timing code.
The browser-check overview averages each metric across the picked window into a Web Vitals chart, and every log row shows a vitals strip with the snapshot for that single run. Each value is colored against the thresholds above. Runs that never call page.goto have nothing to report. FID and INP need real user input and are not collected by synthetic checks.
Packages available in 2026.05
Bundled libraries 12 packages
playwright1.59.1@playwright/test1.59.1typescript^5.6.spec.ts files directly.expect^29uuid^9.0.1lodash4.17.21moment^2.30.1axios^1.13.2btoa1.2.1jsonwebtoken^9.0.2date-fns^2.30.0crypto-js^4.2.0Runtime 2023.04
The 2023.04 runtime runs on Node 16 with Playwright 1.33 and is kept around for existing checks. New checks default to 2026.05 and there's no automatic migration, switch the runtime on the monitor's settings page when you're ready.
playwright ^1.33.0, @playwright/test 1.33typescript ^5.0.4Environment variables
Secrets, tokens, and per-monitor configuration belong in environment variables, not in the script. Add them in the monitor's settings panel below the editor and reference them from the script as process.env.NAME.
Double check
Double check is enabled by default. When a run fails, the runtime immediately retries from a different region before opening an outage. This filters out network blips and one-shot flake without making you wait for the next scheduled run.
Timeouts
Each browser check has a 2-minute global timeout for the entire run. Individual tests inherit Playwright's 30-second default. Override the per-test timeout when you have a slow flow:
test.setTimeout(120_000); // 2 minutes in millisecondsLong flows are usually better split into separate checks, one per critical path, rather than packed into a single 2-minute run.
Run logs and storage
Every run keeps its logs, screenshots, video, and trace indefinitely. Failed runs in 2026.05 attach a video of the run and a Playwright trace to the log row, so you can replay exactly what the browser did.
Example script
A login flow with two assertions, using process.env for credentials:
import { test, expect } from '@playwright/test';
test.beforeEach(async ({ page }) => {
await page.goto('https://app.acme.com/login');
await page.locator('input[type="text"]').type(process.env.EMAIL);
await page.locator('input[type="password"]').type(process.env.PASSWORD);
await page.getByRole('button', { name: 'Sign in', exact: true }).click();
});
test('has title', async ({ page }) => {
await expect(page).toHaveTitle(/Acme/);
});
test('is logged in', async ({ page }) => {
const content = page.locator('#project-id');
await expect(content).toHaveText('project_12345');
});