Last Modified Timestamp

Published in Chrome Web Store: 4/7/2025.

Tired of hunting around for when a webpage was last updated, only to come up empty? This Chrome extension has you covered!

The Goal: To surface the last modified timestamp of any webpage, even if it's not explicitly displayed. We dig deep so you don't have to!

How It Works: We intelligently scan the webpage, checking various locations where a last modified date might be hiding. Our approach follows a logical sequence, prioritizing the most reliable sources first:

1. <meta name="last-modified" content="..."> tag: We first look for the most direct indicator.
2. Other Meta Timestamps: We then explore other meta tags that might contain relevant "updated" or "modified" timestamps. This includes looking at Open Graph (OG) tags like og:updated_time and og:modified_time. If we don't find a "modified" timestamp, we'll also search for a "published" timestamp (e.g., og:published_time).
3. Schema.org Structured Data: Next up, we analyze any Schema.org structured data (in JSON-LD or microdata format) embedded in the page. This often contains accurate publication or modification dates.
4. HTML Content Patterns and Timestamps: If the above checks don't yield a result, we start looking at the visible content of the page. We search for HTML5 <time> elements and common CSS classes that often indicate dates.
5. HTTP Last-Modified Header: As a final fallback, we examine the Last-Modified header sent by the web server. While this can sometimes be less precise (reflecting changes to the server configuration rather than the content itself), it can still provide a useful indication.

In short, we go from the most authoritative sources to the less direct, giving you the best possible estimate of when a page was last changed.

To Use: Simply install the extension. When you're on a webpage and want to know the last modified date, just click the extension icon. We'll do the rest! You'll need to click the icon each time you want to check the last modified date for a page.

Let us know if you have any feedback or suggestions!