Parallel Execution & Sharding in Playwright
From the Playwright cheat sheet · Parallelism & Sharding · verified Jul 2026
Parallel Execution & Sharding
Configure parallel workers and split test suites across CI machines
typescript
import { defineConfig } from '@playwright/test';
export default defineConfig({
fullyParallel: true, // Parallelize within files too
workers: process.env.CI ? 1 : undefined, // Default: half CPU cores
});
// Shard from CLI
// npx playwright test --shard=1/4
// npx playwright test --shard=2/4💡 fullyParallel: true runs tests within a single file in parallel — not just across files
⚡ Sharding splits the full test suite across CI machines — combine with GitHub Actions matrix
📌 Use describe.configure({ mode: "serial" }) when tests in a block depend on each other
🟢 Default worker count is half your CPU cores — set workers: 1 on CI to reduce flakiness
parallelshardingworkersci