Chrome dev tools > the three little dots at the top right of the window > capture full size screenshot.

I always look for it in the three little dots that are next to the 'x' in the dev tools drawer, but it's actually behind the dots in the top nav that show screen dimensions, throttling, device orientation, etc.

Firefox has this built in. That’s how I do it.

https://support.mozilla.org/en-US/kb/take-screenshots-firefo...