Does its main purpose quite well (tested on FF 56), but the addon is pretty much bare bones. No settings or options, no pause, no filters... a shame.

Excellent program. Easy to use, quick, highly recommended.

I use this every few months to efficiently cleanup my busy bookmarks folder.

特别实用的功能，有效帮我筛出失效书签，要是能显示我的中文分类名称就更好了。

Simple, worked well.

Não funciona na versao 68.1 (última pré-autosabotagem da mozilla) ou 80 do firefox mobile para Android mas funciona perfeitamente no PC.

That's so awesome I wish I had money to throw at you guys!

I installed this in Android Firefox I disabled all my other add-ons and this 404 bookmarks did nothing. No results. nada

Works as advertised!

This app needs options to slow it down and to pause the search. its causing my browser to crash and not allowing me to use google due to my email bookmarks activity!

A variety of problems found

I use this handy addon to get rid of all unwanted bookmarks.
Will be hepful if various error codes are handled in different sections.
also many urls with network error are working, maybe you should wait before requesting new outgoing connections ?

I like the idea of it, however, when dealing with several 1,000 bookmarks and lets say a 1,000 are a mixture of 404 or possible 404 its to time consuming to individually select each one so not to include the possible 404.

Maybe group them better (e.g. redirects, timeouts, resource not found, unspecified 40x/50x, server not found, etc.). Allow one to check mark one box scroll down holding shift and click further down and will select everything in that range.

UPDATE 20190911: I decided to start with a fresh profile. In it is a total of 9 bookmarks; 5 of which are the default bookmark preloaded the other are 4 I added. When I run 404 nothing comes back under expired or other which is correct. However, I noticed it reports only 4 unexpired bookmarks rather than 9. So is it intentional to exclude the preloaded bookmarks? NOTE: No Adblockers or any other extension other than 404.

Efficient in finding the dead links, but while doing so, it produces extreme traffic that sends my ISP into red alert and into bugging me with recaptcha checks. Meanwhile, Firefox comes to a halt and crashes from overload. The hit list is not saveable, so there is no other way about it than starting all over again, and going into an into an endless feedback loop. Sadly, I have to uninstall it, though I have no functional replacement for it.

Facile à utiliser et fait le job.

Пользоваться приложением неудобно, потому что нет индикации его работы, и доли сделанного от всего объема запланированных для проверки закладок. Кроме того, отображается название закладки, но не отображается ни путь к ней, ни ее адрес.