It captures the whole page. There is an option preference to always save in a jpg to save file size rather than a png format.

I love this add-on! It is simple, but powerful enough! Great job!

I loved the Pearl Crescent addon before FF57, but WE version is lacking some features:
1) capture the page without visual scrolling ***
2) use hotkey for capturing ***
3) save to Downloads\SUBFOLDER (like Downloads\PageSaver or something user-defined) ***
4) automatic filename increment postfix on name collision (instead of file overwrite) ***
5) some kind of solution to capturing of the fixed elements - for example the fixed footer panel (position:fixed; bottom: 0;) on "https://modnakasta.ua" is repeated on every scroll, instead of being drawn in the actual position (bottom: 0; in this case) or only once (as Screengrab addon does)

The features marked with *** were present in former versions of Pearl Crescent addon and/or are present in current addons from other developers (like mentioned Screengrab addon).

But Page Saver WE works faster on long complicated pages! ;-)

Juste parfait ! :)

I tested Version 3.0.21 (Last Updated: June 22, 2017)
on Firefox 54.0.1 (32 bit) on Windows 8 with 3.5 GB memory.
It installs Ok.
The first page I tested it on was a small reddit subreddit.
It captured the page and opened a save page dialog to save the capture as a PNG file. This worked.

The second page I tested it on was 4chan's Comic and cartoon catalog, not particularly large with small thumbnails.

This also worked, the webpage is longer at 11000 pixels and I noticed the capture took longer.

Note it captures any hover regions as you would see them yourself when scrolling down a page.

I tested it on four more pages, largest size 2.8 MB, smallest 53 KB.

I've been a long time user of the older Pearl Crescent Page Saver, and was looking for a new saver for my new firefox profiles, and this fits the bill.

EDIT: I further tested changing the File name pattern to "%t %Y-%m-%d-%H-%M-%S" - to get finer-grained timestamps - and this worked.

* can take visible portion
* can take full page
* full page is real full page even if the page has a header area that stays if page is scrolled - many other screenshot tools cannot handle that
* has options to configure

- cannot select regions to be captured (please add this feature)
- no keyboard shortcuts
- page needs to be scrolled (do tue web extension?)

- missing option to capture only a region