Here the three most important tips we’ve learned along the way while building our API infrastructure based on Puppeteer to speed up the execution of Chromium browser using Puppeteer library.

Content

1. Use Local Cache

2. Browser Single Launch

3. Inject HTML

Local Cache

Let Chromium to reusing the already downloaded files of previous sessions by setting the --user-data-dir argument when launcing the browser. This way images and fonts will be served much quicker:

'--user-data-dir=./tmpusr'

Of course, this tip works well as much as you reuse same resources across instance calls. If your use-case is about fetching always different websites, this helps very little.

Single Launch

Reuse the same Browser instance instead of lauching it for every session. Launch it on every request is significantly slow:

// keep this reference for next requests
browser = await puppeteer.launch({...})
                                  
// so, don't close it with browser.close()

Reusing the same browser instance is a smart tip, be aware that you have to close it and reopen a fresh browser after a while since it tends to memory leak after a number of uses (depending of your machine, this number can be 20-50 sessions).

Set the HTML

Instead of loading from remote the page you want to process, inject it with page.setContent because it’s faster:

await page.setContent(html)

This is trivial, fetching remote content is significantly slower than using local stuff. Of course, this can be exploited only if your use-case allows to use in-memory pre-loaded assets of assets on local disk.