By frequently crawling and caching pages for the archive, the Wayback Machine has amassed over 366 billion web pages, 20 million books and texts, 4 million videos, and tons of software programs. Now the Internet Archive, the San Francisco-based nonprofit behind the tool, is making it easier to track changes between two snapshots. The new feature, called “Changes,” lets you compare two different archives of a given URL. It gives a side-by-side comparison, with changes highlighted in blue (added content) and yellow (deleted content). Selecting a snapshot is easy. You just tap the relevant dates, and then hit the “Compare” button on top. One of the best uses of this feature I can think of is to track changes in privacy policies. For example, when I queried for Facebook’s data policy changes over the last two years, this is what I got — As you can see from the highlighted blues and yellows, the policy has undergone extensive revisions. This can also be handy if you want to compare a website’s about page, or even check if a news story has been updated over time — However, note that the feature is still in beta and may not always work. When I ran a query with Apple’s privacy policy, the result failed to capture the differences. Also, the tool only compares text changes, so if you’re looking for layout changes or a more detailed history, you’re out of luck. Still, once the bugs are ironed out, there’s no doubt it will be a great way to research a website’s past.