Why are Playwright Tests Slow

Playwright is known for its reliability and flexibility in browser automation, yet teams often encounter slow tests that affect feedback speed and productivity.

This article explores what slow tests are, why Playwright tests might run slower than expected, how to diagnose the problem, and practical strategies to optimize test speed across environments.

What Are Slow Tests?

Slow tests take longer than expected to execute and delay feedback in the testing cycle. They often consume more resources, increase test suite duration, and lead to inefficiencies in CI/CD pipelines.

In automated testing, slow is context-specific. For example, a test exceeding a few seconds in a high-volume suite might be considered slow, even if it passes reliably.

What Are Slow Tests in Playwright?

In the Playwright framework, slow tests usually stem from browser automation delays, inefficient selectors, unoptimized test logic, or poor handling of wait conditions.

These tests may pass consistently but take longer due to repetitive actions, full-page reloads, or slow interactions with backend APIs and UI elements.

Examples Of Slow Tests In Playwright

Here are common test patterns that often result in poor performance:

• Repeating login steps before every test instead of reusing session state
• Waiting for UI elements using waitForTimeout() instead of auto-wait features
• Navigating to the same page multiple times across tests
• Using slow selectors like XPath or overly generic DOM paths
• Performing end-to-end flows where mock APIs could suffice

Each pattern increases the total execution time and creates unnecessary load on the test environment.

Common Causes Of Slow Playwright Tests

Slow tests can arise from multiple factors across test logic, infrastructure, and runtime environment. Below are the most frequent culprits:

• Inefficient Locators: Using unstable or complex selectors can slow down DOM queries.
• Hardcoded Waits: Fixed delays using waitForTimeout() can add unnecessary latency.
• Repeated Setup: Executing full setup logic for each test adds overhead.
• Heavy Navigation: Reloading pages or starting browsers from scratch affects performance.
• External Dependencies: APIs or network services may introduce variability in test time.
• Lack of Parallelization: Running tests sequentially limits execution speed.

How To Identify Slow Tests In Playwright

To optimize test speed, it’s essential to pinpoint where the delays are happening. Below are key methods to help identify slow tests:

• Enable Playwright Tracing: Record and replay test sessions to spot performance bottlenecks.
• Use Built-in Reporters: Capture and log test durations using Playwright’s default reporters.
• Insert Manual Timers: Add Date.now() or custom timers around steps to measure latency.
• Debug With Verbose Logs: Use DEBUG=pw:api to see delays between commands.
• Run in Isolation: Execute tests individually to find which ones are slow.

How To Fix Slow Tests in Playwright

Once you’ve identified slow tests, the next step is to optimize them without compromising reliability.

Below are proven techniques to improve Playwright test speed, along with code examples and expected outputs:

1. Use Auto-Waiting Instead of Timeouts: Avoid hardcoded delays like waitForTimeout() and leverage Playwright’s auto-waiting capabilities for faster, more stable execution.

Inefficient Approach:

await page.waitForTimeout(3000); // Unnecessary static wait

await page.click('#submit');

Optimized Approach:

await page.click('#submit'); // Automatically waits for the element to be ready

Result: Eliminates unnecessary wait time and improves test speed without affecting reliability.

2. Optimize Selectors: Slow or unstable selectors delay element resolution. Use stable, attribute-based, or semantic selectors.

Inefficient Approach:

await page.click('//div[@class="btn"]'); // Fragile XPath

Optimized Approach:

await page.click('[data-testid="submit-button"]');

// or

await page.getByRole('button', { name: 'Submit' }).click();

Result: Faster selector resolution and reduced flakiness across UI changes.

3. Reuse Auth State: Logging in repeatedly across tests adds unnecessary overhead. Save the authenticated session and reuse it.

Step 1: Save Login State

await page.goto('https://example.com/login');

await page.fill('#username', 'user');

await page.fill('#password', 'pass');

await page.click('#login');

await context.storageState({ path: 'auth.json' });

Step 2: Load Saved State in Other Tests

const context = await browser.newContext({ storageState: 'auth.json' });

const page = await context.newPage();

await page.goto('https://example.com/dashboard');

Result: Skips login steps across tests, reducing execution time significantly.

4. Parallelize Tests: Running tests in parallel can dramatically reduce total suite duration, especially in large test sets.

CLI Example:

npx playwright test --workers=4

In Configuration File:

export default {

  workers: 4,

  fullyParallel: true

};

Result: Efficient CPU utilization and faster feedback by running tests concurrently.

5. Mock APIs: Live API calls slow down tests and introduce dependency on external systems. Use page.route() to mock responses.

Example:

await page.route('**/api/user', route => {

  route.fulfill({

    status: 200,

    contentType: 'application/json',

    body: JSON.stringify({ id: 1, name: 'Test User' })

  });

});

await page.goto('https://example.com/profile');

Result: Stable and faster test runs without waiting for real backend responses.

6. Minimize Page Reloads: Full page reloads between tests increase overall duration. Reuse browser context and avoid unnecessary navigation.

Inefficient Approach:

test('Test A', async ({ page }) => {

  await page.goto('https://example.com');

});




test('Test B', async ({ page }) => {

  await page.goto('https://example.com');

});

Optimized Approach:

test.beforeEach(async ({ page }) => {

  await page.goto('https://example.com');

});

Result: Cuts down repetitive navigation time, speeding up suite execution.

Importance Of Testing On Real Devices With BrowserStack

Testing performance only in headless or local environments can hide real-world issues. BrowserStack Automate allows teams to run Playwright tests on real devices and browsers on their real device cloud to validate speed and reliability under real user conditions.

Key benefits of using BrowserStack Automate for Playwright:

• Test on 3,500+ real devices and browser combinations
• Integrate easily with CI pipelines and popular frameworks
• Access logs, videos, and network traces to debug slow tests
• Simulate real network conditions and user environments
• Run tests in parallel at scale with high uptime

Best Practices To Avoid Slow Tests In Playwright

Here are recommended practices to ensure your Playwright tests stay fast and efficient:

• Avoid Using Static Waits: Replace fixed delays like waitForTimeout() with Playwright’s built-in auto-waiting to reduce unnecessary pauses.
• Write Focused Tests: Keep each test concise with minimal setup and teardown to reduce overhead and isolate performance issues.
• Run Tests in Parallel: Use multiple workers to execute tests concurrently and shorten overall suite duration.
• Mock External Dependencies: Avoid reliance on live APIs or third-party services to eliminate network-related slowdowns.
• Use Lightweight Selectors: Choose efficient and stable selectors such as data-testid or getByRole() for faster DOM resolution.
• Cache Browser Binaries in CI: Store browser binaries between builds to avoid re-downloading and speed up test initialization.
• Profile Tests Regularly: Monitor test execution times and review slow steps periodically to catch regressions early.

Talk to an Expert

Conclusion

Slow tests in Playwright can affect team velocity and user confidence in automated pipelines.

By understanding their root causes, applying the right optimizations, and testing on real devices using platforms like BrowserStack, teams can achieve fast, stable, and scalable test automation.

Useful Resources for Playwright

• Playwright Automation Framework
• Playwright Java Tutorial
• Playwright Python tutorial
• Playwright Debugging
• End to End Testing using Playwright
• Visual Regression Testing Using Playwright
• Mastering End-to-End Testing with Playwright and Docker
• Page Object Model in Playwright
• Scroll to Element in Playwright
• Understanding Playwright Assertions
• Cross Browser Testing using Playwright
• Playwright Selectors
• Playwright and Cucumber Automation

Tool Comparisons:

• Playwright vs Puppeteer
• Playwright vs Cypress
• Playwright vs Selenium
• Cypress vs Selenium vs Playwright vs Puppeteer