I built a tool that watches webpages and exposes changes as RSS
I built Site Spy after missing a visa appointment slot because a government page changed and I didn’t notice for two weeks. It watches webpages for changes and shows the result like a diff. The part I think HN might find interesting is that it can monitor a specific element on a page, not just the whole page, and it can expose changes as RSS feeds. So instead of tracking an entire noisy page, you can watch just a price, a stock status, a headline, or a specific content block. When it changes, you can inspect the diff, browse the snapshot history, or follow the updates in an RSS reader. It’s…
I built a tool that watches webpages and exposes changes as RSS launched on March 11, 2026 with 320 votes, #75 of 23,380 launches that month and more than 99% of that year's launches.
In plain words
Site Spy is a browser extension that monitors webpages for changes and displays them as diffs. It lets users track specific page elements rather than entire pages, making it useful for watching prices, stock status, or appointment availability without noise. Changes can be inspected as diffs, reviewed in a timeline history, or followed via RSS feeds. The tool includes a web dashboard and integrates with AI agents through an MCP server, with notifications via browser push, email, or text.
written from the facts on this page · September 2026
From the sources
Site Spy monitors websites for changes automatically. Add any page from the browser extension (Chrome & Firefox) or web dashboard, and get notified the moment content updates. See exactly what changed with visual diffs — additions in green, removals in red. Track specific elements like prices or headlines with the built-in element inspector. Color-coded tags, snapshot timelines, and MCP server integration for AI assistants. Free plan included — no credit card needed
Monitor any website for changes and get notified when it matters. Point at the price, the slot, the headline on a picture of your page — only that reaches you. Free plan, Chrome & Firefox extensions, visual diffs. Visualping & Distill alternative.
Paste a URL, see your page, and click the part that matters — the price, the slot, the headline. Only changes inside it reach you. Click the price, the slot, the headline on the saved page — and only that gets to alert you. Or name the line you are waiting on — "Sold out", "No appointments available" — and get one email the moment it disappears Set a monitor up, ask what changed, adjust how often it checks — in conversation. It opens the picker for you rather than guessing what to follow. Click one element, or drag a box around an area. Land inside a feed and it asks whether you meant that one card or the whole list. Works in the dashboard, in chat and in the extension. We show you your…from sitespy.app
In the maker’s words, at launch
I built Site Spy after missing a visa appointment slot because a government page changed and I didn’t notice for two weeks. It watches webpages for changes and shows the result like a diff. The part I think HN might find interesting is that it can monitor a specific element on a page, not just the whole page, and it…
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