The Wayback Machine has an exciting new feature: it can list the dates and times, the Timestamps, of all page elements compared to the date and time of the base URL of a page.  This means that users can see, for instance, that an image displayed on a page was captured X days before the URL of the page or Y hours after it.  Timestamps are available via the “About this capture” link on the right side of the Wayback Toolbar.  Here is an example:

The Timestamps list includes the URLs and date and time difference compared to the current page for the following page elements: images, scripts, CSS and frames. Elements are presented in a descending order. If you put your cursor over a list element on the page, it will be highlighted and if you click on it you will be shown a playback of just that element.

Under the hood

Web pages are usually a composition of multiple elements such as images, scripts and CSS. The Wayback Machine tries to archive and playback web pages in the best possible manner, including all their original elements.  Each web page element has its own URL and Timestamp, indicating the exact date and time it was archived. Page elements may have similar Timestamps but they could also vary significantly for various reasons which depend on the web crawling process. By using the new Timestamps feature, users can easily learn the archive date and time for each element of a page.

Why this is important

The Wayback Machine is increasingly used in critical procedures such as legal evidence or political debate material.  It is important that what is presented is clear and transparent, even in the light of a web that was not designed to be archived. One of the ways a web archive could be confusing is via anachronisms, displaying content from different dates and times than the user expects. For example, when a archived page is played back, it could include some images from the current web, making it look like the image came from the past when it did not. We implemented Timestamps to provide users with more context about, and in turn hopefully greater confidence in, what they are seeing.