This Add-On was the only one which I found some time ago and which really works to make a screenshot of longer websites.
Thanks a lot!

The only addon I've found that is actually capable of capturing big screenshots (30000+ px height).

This replaces Abduction! as my go-to page image saver. I'm glad at least the concept of full-page image capture has survived the transition to WebExtensions.

Very nice and simple design and could be better if had option to choose image format on its button menu.

I use it whenever I need to remember online data. Very flexible and real time saver.

Works perfectly! Exactly what I was looking for.

All functions work without any issues. Congratulations!!!

Thank you . . . Kathleen Brade and Mark Smith for a wonderfully implemented add-on that does as you stated it would without any surprises or crashes. Finally, someone managed to build a screenshot-er that simply takes a perfect PNG/JPG snapshot and puts it where you tell it to after automatically, properly naming the image in accordance with the url/page title. Couldn't want an app to do it any better than Pagesaver WE!
Haven't tried JPG's yet because historically, PNG takes and renders the best images for such things as a very long website page, and your app completes that task very well, the best I've ever tried so far, and I've tried every available, in-browser screenshot-er app that's come along for many years.
A personal pref on this: Not that you'd mess things up, but I just don't see how this could be improved, its absolutely perfect! - hence, I'm afraid to update since this version simply because it seems like apps, usually through no fault of the creators, just inherently go awry because of browser conflict. So, I'll keep updating Waterfox and leaving this BEAUTY alone until the two become incompatible and I'm forced to update?

THANK YOU BOTH SO MUCH!

Thank you for this excellent extension. It works very well in almost all situations.

Just awesome!

Page Saver is the finest page- or image-saving extension that I've ever seen, by a pretty good margin. Simpler, smoother, more effective, and considerably more flexible than most other browser grab-oids.

AS BEFORE AND ALWAYS: FINE.

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.