It’s barely a week since we looked at the WayBack Machine’s simple Chrome extension, but it’s just had a major update which makes the add-on much more useful.

Clicking the WayBack Machine icon now displays buttons to show the first or most recent archived copies of the current URL, as stored in the WayBack Machine– perfect for seeing how a site has changed over time.

If there’s nothing available – or maybe this is your own site, and there’s not been time for the WayBack Machine to find the URL, yet – hitting “Save Page Now” instructs the service to archive your URL.

As with the previous edition, WayBack Machine’s Chrome extension monitors your browsing, looking for 404 “not found” errors. If a page is missing and the URL has been archived in the WayBack Machine, you’ll get an alert giving you a link to the copy. (Test it here.)

Given that on-demand viewing of WayBack Machine URLs is so useful, we’re not sure why these options weren’t in the first release. But hey, they’re here now, and they make for a much more useful extension, so if you ever use the WayBack Machine with Chrome you’ll want to try this out.

WayBack Machine is the official Internet Archive extension for Google Chrome.