Take a full page screenshot with Firefox on the command-line
Update 2018-07-23
As was just pointed out in the comments, this question was about getting a screenshot from the command line. Sorry, I just read over that. So here is the correct answer:
As of Firefox 57 you can create a screenshot in headless mode like this:
firefox -screenshot https://developer.mozilla.com
Read more in the documentation.
Update 2017-06-15
As of Firefox 55 there is Firefox Screenshots as a more flexible alternative. As of Firefox 57 Screenshots can capture a full page, too.
Original answer
Since Firefox 32 there is also a full page screenshot button in the developer tools (F12). If it is not enabled go to the developer tools settings (gear button) and choose "Take a fullpage screenshot" at the "Available Toolbox Buttons" section.
source: developer.mozilla.org
By default the screenshots are saved in the download directory. This works similar to screenshot --fullpage in the toolbar.
I ended up coding a custom solution (Firefox extension) that does this. I think by the time I developed it, the commandline mentioned in enreas wasn't there.
The Firefox extension is CmdShots. It's a good option if you need finer degree of control over the process of taking the screenshot (or you want to do some HTML/JS modifications and image processing).
You can use it and abuse it. I decided to keep it unlicensed, so you are free to play with it as you want.
The Developer Toolbar GCLI and Shift+F2 shortcut were removed in Firefox version 60. To take a screenshot in 60 or newer:
- press Ctrl+Shift+K to open the developer console (⌥ Option+⌘ Command+K on macOS)
- type
:screenshotor:screenshot --fullpage
Find out more regarding screenshots and other features
For Firefox versions < 60:
Press Shift+F2 or go to Tools > Web Developer > Developer Toolbar to open a command line. Write:
screenshot
and press Enter in order to take a screenshot.
To fully answer the question, you can even save the whole page, not only the visible part of it:
screenshot --fullpage
And to copy the screenshot to clipboard, use --clipboard option:
screenshot --clipboard --fullpage
Firefox 18 changes the way arguments are passed to commands, you have to add "--" before them.
Firefox 88.0 has a new method for taking screenshots. If extensions.screenshots.disabled is set to false in about:config, you can right-click the screen and select Take Screenshot. There's also a screenshot menu button you can add to your menu via customization.
You can find some documentation and the full list of commands here.
PS. The screenshots are saved into the downloads directory by default.