Sometimes overreacts when page loads for a long time. I would prefer to not get modal dialog blocking page that loads correctly.

So far it's alright, and it does what it says on the tin. However, it is probably too eager to prompt the user to check the 404 page. On many occasions where the page did load, its modal window pops in my face asking me to check out any archived versions.

Worse still, the popup is a modal window that blocks out the rest of the page and cannot actually be exited out of without reloading the whole page.

Personally, I think it would be fine if there was no pop-up at all. Simply have the user access the toolbar button.

Seems to overreact with resource loading errors within the page.

This is not really properly tested.

This addon absolutely has some use in concept but it takes over pages loading slowly or differently - even fast loading consisten pages on some websites I visit.

I wish it worked, I wish there was a minimum configurable timer, and I wish I could set it to ONLY come up on ACTUAL 404's.

Instead, I'm just going to disable it for now and see if it ever gets better. Sadly it is far more in the way than helpful.

Have been using this since it was a Firefox Test Pilot project called "No More 404s". Never had any problems with it. It's one of those features that should be built into Firefox.

It's nice to be able to look up or save a page from the button. The automatic feature might be helpful if it was not a false positive 95% of the time. An option to turn that off would be worth a star to this review.

it seems overzealous, maybe an error loading some part of the page triggers the extension to assume the entire page is unreachable? that's my guess- I'm not sure exactly what is triggering the false positives exactly. has worked a few times as intended/expected, too

Often shows some giant wayback image for urls that are working. Actually it seems to think that there is an dns error while there is none. Not usable in this state.

Please only hijack the error pages (404 and dns error) and provide a link there to the wayback machine. That would be perfect. And thanks for wayback machine.

Constant false-positives, causing the giant Wayback Machine image to appear over an otherwise valid, working page, and causing me to loose all of my forward navigation history. Had to remove due to this extreme annoyance. Instead, it should simply show an icon in the address bar when an archived version of a page is available.

Too eager! Every time it's come up, I got the desired page by clicking the link again. It's never provided a backup page that was needed.

Useful, but there are too many cases where are page just happens to load too slowly for the extension's taste so it pops up offering to use the service, blocking the entire page.

It would be nice if it would really only show up when the page is 404 and not because the page is coincidentally loading slowly.

Sometimes there are false positives, and I have to turn off the add-on to view the site.

So useful add-on.

But there is a problem with the context menu: When you right click on a link and select an option (like First Version) it shows the current site that you are visiting (the URL at your address bar) instead of the URL you clicked on.

I don't know if it's a bug or a feature but It would be very useful if it opens the link you right clicked upon :/

Also there is a bug unique to Firefox; if URL is not found, nothing happens. In Chrome it warns with a pop-up message.

Thank you for this add-on and glorious Archive.org itself <3

A nice extension. Generally works but occasionally has hiccups.

That said, updating to the newest version needlessly cluttered up my context menu with duplicates of the stuff available through the browser action (that I currently have to resort to userChrome.css to remove) and non-optionally added a requirement for notification privileges with no option to turn off whatever annoying popup it's planning to display.

I'm giving it a 3 out of 5 for those warts.

Works perfectly.

Extremely useful. The new update is great

The Internet's backup.

Very useful, but buggy. Keeps trying to wayback sites that actually load and work.