Viewport resizing to window size

[Shivam93937]

FAQ

• Yes, my issue is not about variability or throttling.
• Yes, my issue is not about a specific accessibility audit (file with axe-core instead).

URL

https://google.com

What happened?

When running from CLI, is there an option to by default set the viewport according to the window size because it resizes to cover the window size after certain amount of time.

What did you expect?

I expected that the viewport should automatically be sized to window size.

What have you tried?

I have tried changing the puppeteer launch options, via lighthouse configurations, and screenemulation options.

How were you running Lighthouse?

CLI

Lighthouse Version

11.7.1

Chrome Version

No response

Node Version

20.11.0

OS

Windows

Relevant log output

No response

[adamraine]

The CLI flag --screenEmulation.disabled should prevent Lighthouse from changing the emulated screen size. Also available on the config:

const config = {
  extends: 'lighthouse:default',
  settings: {
    screenEmulation: {disabled: true},
  },
}

Are you using Puppeteer as well?

[Shivam93937]

Yes I am using puppeteer as well

[adamraine]

puppeteer.connect applies it's own emulated screen size by default. Try using defaultViewport: null on the connect options puppeteer.connect({browserURL: 'http://localhost:9222', defaultViewport: null})

[Shivam93937]

Do you have any idea how to emulate mobile screen without resizing viewport to window size?