It's perfect. Thanks Manuel.

Best screenshot extensions in the shop. Saves PNG images of full page without compression!

I really like this tool, because it is fast and very easy to understand and use (also for older users, not only for experts). Thank you!

一键全网页截屏 很好

I just tested about 6 or 7 different screenshot extensions — including the big ones like Nimbus, Awesome Screenshot, and Fireshot — and Save Screenshot by Manuel Reimer was the only one that could actually (and COMPLETELY capture and) save the huge webpages I needed to screenshot for archiving purposes. Not only was the capturing process itself much faster the others I have tested in the past, it captured the entirety of the first webpage (in one try) as a 26.5 MB PNG file without any unnecessary loading, superfluous options, or other fluff that normally gets in the way of performing what should be a simple task in a timely manner. It delivered and did everything it promised to do for me as of November 8th, 2018 on my Firefox 62.0 Portable browser — in private browsing mode no less with a VPN on without needing to tweak anything beforehand.

*Funny story about this extension:

I had been so frustrated with the repeated failures of the other webpage capture extensions that, when I didn't see an immediate reaction to hitting the screencapture button, I assumed it wasn't working like all the others and uninstalled it immediately — within seconds because I had my extensions tab open for quick access. To my dismay the "save file as" window popped up almost immediately after I had uninstalled it. I was still able to save the image despite the extension being uninstalled and immediately undid the uninstallation once I realized it had worked. Talk about a close call.

Been looking a long time for a one click-solution that quickly and correctly gets what I want done - thanks!!!

很棒！可以在安卓上使用的长截屏扩展！

It s very useful and simple! Thanks!

Gutes Tool um Bildschirmfotos nicht in die Cloud laden zu müssen, wie bei der Firefox Erweiterung.

Simple without being too simple - this addon creates a whole page screenshot and then shows a download dialog.

просто супер ! легко ,удобно , работает !!!

Would be perfect if it could ACTUALLY capture the WHOLE really loooonng webpage like extensions in Chrome do. I'm not sure if it is a Firefox Quantum's shortcoming or something but it just can't capture to the end of webpages of extreme length, the lower part of the page is just white and blank. Please look into this problem. Thank you!
P/s: You can test on one long scrolling webpage like this one: http://psychologytoday.com/ and you will get what I mean.

I really like this minimalist app, very useful. unfortunately it stopped working in firefox 58.0 (Mac) :(
Thanks for the good work

Minimalist perfection. Don't change it. Thank you.

Superb.
Most importantly for me it allows you to capture a page zoomed out while maintaining capture resolution (i.e. it allows above native screen resolution capture). This is the only WebExtension I've found that does. I hope this never changes.

Add to that a minimalist approach without any superfluous services or tools, just capture visible/full page and jpeg/png: It's basically perfect.

素晴らしい！！！　私の求めていたものはこれだ！！！　
[ワンクリック] → [既定のソフトで開く]　or [保存] の簡単操作！！
こういう説明不要。　何も考えずに使える簡単なAddonがベスト！

ただ、問題点としては保存先が強制的にDownloadになること。
これはデスクトップのほうが有り難い人にとっては、都度変更しなければならない不便さがある。

--2017/12/15--
Firefoxの設定から既定の保存先をデスクトップに変更することでデスクトップが保存先として選べるようになりましたが、他のDownloadファイルも全てデスクトップに保存されるため、完璧とはいえません。
ただ、以前使用していた Perl Crescent Page Saver がScreen shotの保存先を任意に設定できたので便利でした。そのアドオンは、現バージョンのFirefoxには未対応で、同作者の後継アドオンは以前より使いにくくなったので、こちらを使用しています。