Yep, changedetection.io is a good project. With Site Spy, I wanted to make the browser-first workflow much easier: install the extension, connect it to the dashboard, click the exact part of the page you care about, and then follow changes as diffs, history, or RSS with very little setup. I can definitely see why the open-source / self-hosted route is appealing too.

Changedetection has an extension too: https://chromewebstore.google.com/detail/changedetectionio-w...

Does your project use changedetection.io behind the scenes? When I look at the _All Watches Feed_ the contents of the rss file include;

    <?xml version='1.0' encoding='UTF-8'?>
    <rss xmlns:atom="http://www.w3.org/2005/Atom" xmlns:content="http://purl.org/rss/1.0/modules/content/" version="2.0"><channel><title></title><link>https://changedetection.io</link><description>Feed description</description><docs>http://www.rssboard.org/rss-specification</docs><generator>python-feedgen</generator><lastBuildDate>Thu, 12 Mar 2026 10:10:10 +0000</lastBuildDate></channel></rss>

Yes — it's a fork of changedetection.io. I went into more detail here: https://news.ycombinator.com/item?id=47349141. The RSS link you spotted was a leftover, already fixed

see:

https://news.ycombinator.com/item?id=47349069

There's also https://github.com/thp/urlwatch/ - (not aware of any SaaS offer - self-hosted it is).

Yep, urlwatch is a good one too. This category clearly has a strong self-hosted tradition. With Site Spy, what I’m trying to make much easier is the browser-first flow: pick the exact part of a page visually, then follow changes through diffs, history, RSS, and alerts with very little setup

Looks cool and this can be self hosted and it is for free.

Nice will try this out!

Sure but this one has a MCP server, costs money, and was presumably made last night!

It's been around for a while and recommended by many. I tried it myself and it's okay.

Are you referring to OP's site? The domain was registered 2026-01-16 so it certainly hasn't been around for a while.