Setting a user agent

The User-Agent request header is a characteristic string that lets servers and network peers identify the application, operating system, vendor, and/or version of the requesting user agent.

Many sites use this information to render the site differently for each user, and sometimes even for rudimentary bot detection. If you run chrome headless and want to take a screenshot of a page, it's a good idea to set a user agent so that web fonts load properly.

Code

You can set the user agent from code, in puppeteer it would be like this:

await page.setUserAgent(
  'Mozilla/5.0 (Macintosh; Intel Mac OS X 10_14_0) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/84.0.4147.125 Safari/537.36'
);

REST API

If you're using our APIs like /screenshot, /content, /pdf, or /scrape, you can also set the user agent in the body of your request.

{
  "userAgent": "Mozilla/5.0 (Macintosh; Intel Mac OS X 10_14_0) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/84.0.4147.125 Safari/537.36"
}

Hosted service

If you're on a usage-based, cloud unit-based or capacity-based account, you can change the user agent as so

const browser = await puppeteer.connect({
  browserWSEndpoint:
    'wss://chrome.browserless.io?token=YOUR_API_KEY&--user-agent=Mozilla/5.0 (Macintosh; Intel Mac OS X 10_14_6) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/100.0.4896.127 Safari/537.36',
});

Self-hosting

If you're self hosting, you can set the user agent as a default launch argument.

    docker run -e "DEFAULT_LAUNCH_ARGS=[\"--user-agent=Mozilla/5.0 (Macintosh; Intel Mac OS X 10_14_6) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/100.0.4896.127 Safari/537.36\"]" -p 3000:3000 --restart always -d --name browserless browserless/chrome