Intercept and modify requests

CDP Fetch.enable lets you inspect, block, or modify every request the page makes.

Block by resource type

Puppeteer:

await page.setRequestInterception(true);

page.on('request', req => {
  if (['image', 'media', 'font'].includes(req.resourceType())) {
    req.abort();
  } else {
    req.continue();
  }
});

Playwright:

await page.route('**/*', route => {
  if (['image', 'media', 'font'].includes(route.request().resourceType())) {
    route.abort();
  } else {
    route.continue();
  }
});

Block by URL pattern

// Puppeteer
page.on('request', req => {
  const url = req.url();
  if (url.includes('google-analytics.com') || url.includes('doubleclick.net')) {
    req.abort();
  } else {
    req.continue();
  }
});

// Playwright
await page.route(/google-analytics\.com|doubleclick\.net/, route => route.abort());

Modify headers

// Puppeteer
page.on('request', req => {
  req.continue({
    headers: { ...req.headers(), 'X-Custom': 'value' },
  });
});

// Playwright
await page.route('**/*', route => {
  route.continue({
    headers: { ...route.request().headers(), 'X-Custom': 'value' },
  });
});

Return a fake response

// Puppeteer
page.on('request', req => {
  if (req.url().endsWith('/api/feature-flags')) {
    req.respond({
      status: 200,
      contentType: 'application/json',
      body: JSON.stringify({ newDashboard: true }),
    });
  } else {
    req.continue();
  }
});

// Playwright
await page.route('**/api/feature-flags', route => {
  route.fulfill({
    status: 200,
    contentType: 'application/json',
    body: JSON.stringify({ newDashboard: true }),
  });
});

Strip analytics in production scrapes

const BLOCK = [
  'google-analytics.com',
  'googletagmanager.com',
  'doubleclick.net',
  'facebook.net',
  'segment.io',
  'mixpanel.com',
  'hotjar.com',
];

page.on('request', req => {
  if (BLOCK.some(host => req.url().includes(host))) {
    req.abort();
  } else {
    req.continue();
  }
});

Built-in: --stealth ships with a tracker blocklist that handles most of these without per-script setup. See Configure stealth and proxies.