Know the moment the web changes

Up and running in four simple steps

No setup and no account. Add ArcWatchtower and start watching in under a minute.

1. Install the Chrome extension

   Add ArcWatchtower to Chrome in one click. It is free, with no account required.

2. Open any website

   Go to any page, feed, or API you want to keep an eye on.

3. Activate the extension

   Pick the whole page or a single element, and set your check schedule.

4. Get instant results

   ArcWatchtower alerts you the moment it changes, with a clean diff.

Built to catch the change, and skip the noise

Everything you need to monitor the web precisely, from a single price to an entire portal, without the false alarms.

• Element-level watching

  Watch a single price or label, and ignore the rest of the page.

• Every alert channel, free

  Telegram, Slack, Discord, push, and webhooks on your own endpoints.

• Price and stock trends

  Chart a number over time and alert when it crosses your threshold.

• Keyword and ignore filters

  Alert on the words that matter, and mute regions that always change.

• JSON and API monitoring

  Point it at a JSON endpoint and it diffs the response, not the noise.

• Runs locally, private

  Monitoring happens in your browser. Your history stays on your device.

Why teams put ArcWatchtower on watch

It is not just about catching changes. It is about catching the right ones, first, without leaking a thing.

• Never miss a move

  Be first to a price cut, a restock, a new posting, or an incident.

• Cut the noise

  Element watching and filters mean you only hear about what matters.

• Keep it private

  Local by design, so pages behind a login work and nothing leaves your device.

• Start free, scale simply

  Five watches free, then a flat price when you are ready for more.

Simple, transparent pricing

Start free and upgrade anytime. No hidden fees, no surprises, and you can cancel whenever you like.

Questions, answered

Everything you might want to know before you add ArcWatchtower to Chrome.

What is ArcWatchtower?

ArcWatchtower is a Chrome extension that monitors any web page, feed, or API for changes and alerts you the moment something changes. You can watch a whole page or a single element, and get a clean before and after of what moved.

How does website change monitoring work?

You add a page or element to watch, ArcWatchtower takes a baseline, then re-checks it on your schedule and compares each new version to the last. When the meaningful content changes, it sends you an alert with a diff.

Is ArcWatchtower free?

Yes. The free plan includes 5 watches, checks every 6 hours or daily, and every alert channel, with no credit card required. Pro adds more watches, faster checks, and advanced filters for 9 dollars per month or 79 per year.

Can it monitor pages behind a login?

Yes. Because ArcWatchtower runs in your browser, its checks reuse your existing session for that site, so pages behind a sign-in are monitored as you. No password ever leaves your device.

Can it send alerts to Slack, Telegram, or Discord?

Yes, and these are free on every plan. You connect your own Telegram bot, Slack or Discord incoming webhook, ntfy phone push topic, or a custom webhook, and ArcWatchtower sends each change there.

Can it track price or stock changes over time?

Yes. ArcWatchtower can pull a number from the page, such as a price or stock count, chart the trend over time with a sparkline, and alert you when it crosses a threshold on Pro.

Can it monitor an API or JSON endpoint?

Yes. Point it at a JSON endpoint and it diffs the structured response and ignores cosmetic key order changes, which is ideal for status JSON and data feeds.

Is my data private?

Yes. ArcWatchtower watches pages locally in your browser, your history is stored on your device, and no external server monitors your pages for you.