Related to What sort of mechanisms are used by Web applications to track my actions? I would like to know:

What tools, scripts or other applications can be used to identify when my online activity is being monitored or tracked by Web applications or sites?

3 Answers 3


Do Not Track Me and Disconnect are similar browser extension tools to Ghostery. They will show you trackers on each web page in the browser, and let you block them.

Other useful tools are ad blockers (not that the ads per se are a problem, but the tracking that comes with them is), and JavaScript blockers like NoScript (or JavaScript Blocker in Safari).

You may have to (selectively) disable some of these extensions from time to time to allow certain web sites to function properly.

In addition to HTML cookies, there are also other first-party means of silently collecting information about your visits. Web sites always have access to your IP address (and therefore also your approximate geolocation), port number, host name of your machine if it exists, your User Agent, and other details about your browser. With JavaScript, web sites can easily access your display size, your browser window size and position, browser plug-ins you have installed (which often enable detecting which fonts you have installed), the number of pages in the history of the current tab, possibly the web page that referred you to the current page, and other information about your browser environment.


Ghostery is a (but certainly not the only) browser extension that alerts you to certain trackers/companies as you surf online.

Ghostery tracks over 1,400 trackers and gives you a roll-call of the ad networks, behavioral data providers, web publishers, and other companies interested in your activity.

I use it both to block tracking and as an alert for when I'm being tracked.

MyPermissions can help you monitor and clean up applications' access to your information- you can both revoke and customize which applications have access to what information, just in an easier-to-use interface than doing so directly from each app. You can also set it to alert you when your information is being accessed as well as set regular reminders to go through and clean up your permissions.

There are many similar tools out there, but these two are among the most useful.


There is a Firefox add-on called Collusion that will also show you who is tracking you and what site they are tied to.


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