I have been collecting bookmarks for 5 years, and this is a wonderful extension to have. Over 3000 expired (404) bookmarks.

There is no stop function when searching through bookmarks, and you always have to scroll down to select them. This may be fine with a few hundred bookmarks, but with thousands of bookmarks it's annoying. You have to wait forever for the list to be processed. And Firefox's performance drops dramatically during this time. With a stop button, you could pause the search to sort through the results. But then the select button has to be at the top, because it always moves with the bookmarks found. Terrible!

Couldn't be simpler. I installed, ran the extension from the extensions overflow menu, and it sorted through my 90,000 bookmarks in a fairly reasonable time.

Dang there's a lot of dead sites :(, I am still confirming most of them (and will be for a while!) but it makes me sad to see so many resources and websites gone.

これは便利！

No user interface, no instructions, absolutely nothing to guide use of this extension, rendering it useless. I'd like to know how those users who are giving high ratings managed to use this.

To launch: in "Extensions" (puzzle icon). Does what it is designed for

This extension has no instructions and no intuitive interface; in fact it has no interface or way to execute it at all.

No controls: no menu add-ons, no rh-click context sensitive button, nothing. It might work well if only I could figure out how to run it...

This Addon is awesome! Does exactly what is needed and possible, I was looking for something like this and its actually there!

I am quite shocked how many of my bookmarks are offline... like the web was dying.

Also very useful on TorBrowser to see if onion sites are down.

Still works!

404 Search should:
- note URL of bad bookmark in list generted
-search following order in the Bookmark tree in Firefox ...subfolder path should be shown

- bookmark title should be searched for within site as sometimes things are still there but located differently
-bookmark should be searched in Google (or other search engine) as it can sometimes still be found
-a csv list that can export bookmark name/URL/Path in Bookmark tree/Date added etc. would be helpful

The additional search features noted above could be run after the initial list is generated if this makes doing this easier

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.