Guide

What is website change monitoring?

Website change monitoring is software that checks web pages you choose on a schedule, compares each version with the previous one and tells you when something changed. It replaces opening the same pages by hand to see whether anything is different. What counts as a change is up to you: a paragraph of text, a price, a stock label or a technical field in the page code.

How it works

Tools differ in the details, but the steps are much the same everywhere.

1. You give a URL and say what to watch: the whole page, one part of it or a single value such as a price.
2. The tool fetches the page at a set interval, for example every hour.
3. It compares what it fetched with the last version it stored.
4. It filters out noise, meaning the parts that change on every visit without mattering: dates, counters, rotating banners.
5. If a difference remains, it alerts you, usually by email or in a chat channel, and keeps the old and the new version so you can see what changed.

What can be monitored

Most tools offer several kinds of check. The common ones are:

• TextThe visible content of a page. People watch it to learn when a competitor rewrites an offer or when their own page is edited without notice.
• A single elementOne area of the page chosen with a CSS selector. The check stays on the part that matters and ignores the rest of the page.
• PriceThe price of a product. Shops watch it to know when a competitor changes a price or when their own price is displayed wrongly.
• Stock and availabilityWhether a product is in stock or sold out. It shows when an item comes back or runs out.
• SEO fieldsTitle, meta description, H1, canonical and robots. A changed canonical or a noindex added by mistake can affect how a page appears in search without anyone seeing it on the page.
• JSON and API responsesThe structure and values an API returns. Developers watch them to learn when a field is renamed, removed or changes value.
• SSL certificate expiryThe date a site's certificate expires. An expired certificate makes browsers show a warning to visitors.

Who uses it and for what

These are typical uses, not customer stories.

• eCommerceFollowing prices and stock, your own and competitors', to react to a price change or to catch a wrong price in your own shop.
• SEOCatching unintended changes to titles, canonical tags or robots directives after a release or a CMS update.
• Legal and complianceKnowing when a supplier or a platform changes its terms, privacy policy or other published conditions.
• AgenciesKeeping an eye on client sites, so that a change made by the client or by a third party does not go unnoticed.
• DevelopersWatching the responses of APIs they depend on, to find out when a response changes structure or values.

Its limits

Change monitoring is useful, but it has clear limits that are worth knowing before you rely on it.

• It sees only what the page serves to an automated visitor. Content shown only after login, after a click or to visitors from a certain country may be missing from what the tool receives.
• Sites can refuse automated access, through robots.txt or anti-bot protection. A tool that respects these rules does not get around them, so some pages cannot be monitored.
• Pages built only by JavaScript, in the browser, need a real browser to be read. A simple fetch receives an almost empty page.
• The check interval decides how soon you find out. With hourly checks, a change can be up to an hour old when you hear of it. It is never instantaneous.
• Noise causes false alerts. Dates, counters and rotating banners change on every visit and have to be filtered, otherwise you receive alerts that mean nothing.
• It is not uptime monitoring. A change monitor tells you that content changed, not that a site is down or slow; that is a different kind of tool.

What to look at when choosing a tool

A few neutral questions help when comparing tools:

• Which kinds of change does it understand: only text, or also prices, stock, SEO fields and API responses?
• Which check intervals does it offer, and on which plans?
• Through which channels does it alert you: email, chat apps, webhook?
• How does it filter noise, and can you limit a check to one part of the page?
• How long does it keep the history of versions and changes?
• Is the price based on the number of pages or on the number of checks?
• Does it respect robots.txt, and does it say clearly what it does when a site refuses automated access?

How OmniWatchGuard does it

OmniWatchGuard has monitors for text, price, stock, an element chosen with a CSS selector, SEO fields, JSON/API responses and SSL certificate expiry. Checks run every 60 minutes on the Starter plan, every 15, 30 or 60 minutes on Pro and every 5, 15, 30 or 60 minutes on Agency.

An AI model summarizes each change and rates it minor, major or critical. Alerts are sent for major and critical changes only; minor ones are recorded in the dashboard. It works on sites that allow automated access: the crawler respects robots.txt and does not bypass anti-bot protection. The free trial lasts 10 days, needs no card and allows up to 3 monitors, checked every 60 minutes.

More detail:

• Product facts
• Pricing
• Comparison with other providers
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