Web Page Change Tracking

Often, you want to detect changes on some eBay offerings or get notified of the latest items of interest from craigslist in your area. Or, you want to monitor updates on a website (your competitor’s, for example) where no RSS feed is available. How would you do it, by visiting it over and over again? No, now there are handy tools for website change monitoring. We’ve evaluated some tools and would like to recommend the most useful ones that will make your monitoring job easy. Those tools nicely complement the web scraping software, service and plugins.

General categories

Website tracking utilities may be put into 3 categories:

1. Browser plugin/add-on
2. Service
3. Application

When using a browser plugin/add-on or a desktop application to detect changes, the pages are tracked only when your computer is on. Emails/RSS notifications from a monitoring service work well if you are out of the office and want instant (often with a delay, like Page2Rss) changes on your mobile device. Applications and plugins are the most powerful tools since they’re likely to report with minimum delay; they inform you of the changes right away. Being able to compare changes in the same window is a convenient feature, although most of the time you will need only the new values without the previous ones. Page Monitor excels in that aspect, posting both the new and previous values side-by-side on the screen.

Page Monitor

Page Monitor is a Google Chrome extension that works perfectly for  detecting changes in any number of websites. It uses a smart comparison system that ignores ads and code changes. The tracking interval is customizable for each page, starting from 5 sec. It sends a popup to the system tray with a link to the website as soon as it changes. Notifications may also be set to sound alarm. You may select an area of a website to monitor or check if there is a word(s) on a page and also apply a regex. Both old (in red) and new (in green) data are highlighted:

Update Scanner

This free monitoring tool is a Firefox browser add-on. The user may select how often each site will be scanned. New content that has been added to a page is highlighted. The sound alert may be turned on or off. Autoscan time is adjustable, starting from 5 min. The change threshold, including whether changes in numbers should be ignored, may be selected, depending on your needs. But, compared to previous tools, this add-on doesn’t show what has been removed from a website.

InfoMinder

This service is easy to set up and works smoothly. I like it because in an alert email there is a link to the page changed with changes highlighted, as well as the initial text so it’s immediately clear what has been changed. The free trial plan tracks up to 10 pages free of charge for 30 days. InfoMinder offers extensions for browsers (IE or FF) to make it easy to track any website while browsing. It’s possible to filter what changes to detect. After a trial period, you may upgrade to Pro or Premium plans and get your websites quota increased, as well as a monitoring frequency (up to 6 hours for each), with the price starting from $30/year per 100 pages. See the webpage snippet with red text and yellow background highlighted changes:

The free analogue to this service is ChangeDetection. With a simple UI it allows monitoring on a daily base with email notifications. The drawback is that it tracks and then logs only text updates, which is not convenient to check later.

Website Watcher

This professional, fully-featured monitoring application allows website changes tracking, including comparison of the new and old pages side-by-side. It can notify you when a monitored website has been updated and when chosen expressions or text are detected on a web page. Website Watcher checks websites automatically with the AutoWatch feature or you may manually invoke a check for updates. Filters can be created automatically with the Auto-Filter system, or manually. Also, local files may be placed under its oversight and changes are highlighted. The Basic edition costs about 29,95 Euro (approximately $40 US) with Personal and Business editions priced up to about 10000 Euro. See the versions compared in two columns in the application inbuilt browser:

Its free analogue is NotiPage. It’s also a Windows utility for monitoring websites with basic monitoring features, warning you by a visual and audible alert. The difference between NotiPage and Website Watcher is NotiPage has fewer features and, specifically, it doesn’t show you what has been removed from a page.

Recap

Summary of which monitoring tools work best for a specific use:

• If you work at home at a computer – browser plugins or applications work well, giving screen messages.
• If you are out of the office most of the time with a mobile device on – sign up for a change detection service to get instant emails or RSS feed.
• If  you want advanced ability to supervise – chose Website Watcher or another similar to it.
• If you want to check the updates with a filter on – Website Watcher, Page Monitor or InfoMinder services work well.
• If you want to detect changes in an unlimited number of websites or detect very frequent changes – use Page Monitor or Update Scanner.
• If you need auto backup or checking new and old versions side-by side – go with Website Watcher.
• If you want to track a specific text on websites – use Page Monitor service.