[Feature request] Make it possible to control the zoom level via the API

Steps to reproduce

It would be great if you could control the zoom level via the API. Perhaps as part of setViewport or with a new function call.

What is the expected result?

You should be able to control the zoom level via the API.

What happens instead?

You cannot control the zoom level 😁

[aslushnikov]

@JoelEinbinder the zoom discussed here is what we call "scale" in chromium-land.

@36degrees since there’s not much demand for this, I’d recommend you falling back to the raw devtools protocol for this.

There’s a method Emulation.setPageScaleFactor that let’s you do what you want.

BEWARE! Emulation.setPageScaleFactor is an experimental method, so it might change/go away in some future Chromium releases.

const puppeteer = require('puppeteer');

(async () => {
  const browser = await puppeteer.launch({headless: false});
  const page = await browser.newPage();
  await page.goto('https://vanilla.aslushnikov.com');
  const session = await page.target().createCDPSession();
  await session.send('Emulation.setPageScaleFactor', {
    pageScaleFactor: 4, // 400%
  });
})();

If there’s more demand in future, we can actually expose the method to Puppeteer and commit to its support.

Hope this helps.

[36degrees]

That doesn’t appear to do the same thing as zooming the page – specifically, in my testing at least, it didn’t appear to trigger breakpoints.