Docs

Look at the state on “Pages being monitored”. If it says “Could not fetch”, the fetch failed — it is not that there was no change. A failed fetch is never treated as “No change”.

If the state is “No change”, what you selected really has not changed.

If the state says “Updated” but you did not notice, check that “Show browser notifications” is on under “🔔 Notifications” in the sidebar. Sending to Discord, Slack, Teams, Google Chat or ntfy is configured on the same screen.

No. It only learns what the page looks like at that moment; nothing is reported. Changes from then on are what you hear about.
The same applies when you change a setting that affects comparison (the area, the mode, the exclusions): it relearns the content and stays quiet.

An advert slot, or a relative timestamp such as “3 minutes ago”, is probably caught in the selection. Put that part into “Places to remove”. Relative timestamps are ignored automatically by default.
If that is not enough, change the mode to “Text changes”, or set a minimum amount of change under “Changes to ignore”.

The area you first chose can no longer be found, and monitoring is continuing through another way of pointing at the same element. Monitoring has not stopped, but it is a sign that the site has begun to change.
The fallback can stop working too, so reselecting the area sooner rather than later is wise.

Most pages can be fetched, but pages that require signing in, and sites that block access, cannot be monitored.
Checking the terms of the site you monitor is your own responsibility.

No. This extension runs only inside your browser. While the machine is asleep, or the browser is closed, no patrol happens.
It catches up the next time you start it, and tells you if something changed. The notification marks the moment it noticed, not the moment it changed.

It is a browser extension, so it does not run on a phone.
Set up a webhook, though, and the notifications reach your phone. Keep the monitoring running on a computer and read the notifications on the phone.

Unless you set it up, what you monitor is not sent. Fetching, comparing and storing happen in your browser.
Only if you configure a webhook do updates reach the destination you chose.
There is also a setting that sends the kind of action and how often, but it is off by default. Neither the URLs you monitor nor what was fetched are ever included. See “🔐 How your data is handled” for the detail.

No. It is free, with no advertising and no affiliate marketing. No account is needed.

Use “✉️ Send feedback or a request”. Besides bugs, pages that don’t monitor well and feature requests are welcome too.
With a bug report, please include what “📋 Copy diagnostics” copies. It does not include the URLs you monitor or the content fetched.