Adobe Flash Cookies: Hidden Web History

Think deleting your web history and cookies from within your web browser deletes all traces of where you’ve been and what you’ve been doing from the prying eyes of peers and advertisers? Think again.

Adobe Flash has its own private storage within your computer which is inaccessible from any browser’s history deletion system – regardless of the browser being used. This post provides more information about said “Flash cookies“, how they’re used, and how to view/delete them.

What’s a “Flash Cookie”?

Just like regular cookies, its nothing more than a small piece of data stored within your web browser’s local hard drive storage directory that is used to store information about you between web pages.

Cookies by themselves are not privacy risks – they’re used to keep you logged in and to keep other similar sessions intact. It’s how they’re used (or abused) that makes them a privacy concern.

Flash cookies differ in that they’re stored differently than other cookies – instead of being placed into the browser’s cookie storage, they’re placed in a separate, (by default) browser-inaccessible location, which means that a cookie without an expiration date will remain there indefinitely.

The bad part is that they can be retrieved from any website, most notable cross-site advertisers, to “track” a user’s browsing habits and where they’ve been.

How To Delete Flash Cookies

Convinced that its time to delete them? Or even better, want to just view these cookies and experience a little deja vu?

Macromedia Adobe has a little utility on their website, called the “Flash Settings Manager“, which allows one to view and/or delete these cookies. It is accessible here.

You might find some interesting stuff in there, especially if on a shared computer.

Better Privacy Practices

If you use Mozilla Firefox as your web browser (and, for all practical purposes, why wouldn’t you?) then there’s an addon that lets you automate the deletion of Flash cookies with every browser shutdown.

It’s called BetterPrivacy, and is downloadable here.

What To Think of All This

We cover privacy and Macromedia Adobe products (typically in a bad light) frequently on this site, but really – Adobe isn’t evil. They just have a bad history of their products being used as such.

Now, Macromedia Adobe could have placed Flash cookies within the same directory as the other cookies a browser uses so they could be deleted without a trip to Macromedia Adobe’s website, but they didn’t.

And again, this wouldn’t be such a big deal if the cookies automatically deleted themselves rather than sitting there, waiting to be viewed by prying eyes (through the settings manager, no less) or if the cookies weren’t used by advertisers to track users’ online activity.

But they are, so be aware and delete your cookies. This isn’t about covering up what naughty sites you’ve been to, but it is a privacy issue that everyone should be aware of.

And, that said, I leave you with a humorous image relevant to this post :) .

The Cookie Monster deletes his cookies, too


Mark (who wishes to keep his last name private) is currently employed as a system administrator for a company in his hometown. He has extensive experience in both networking and programming, and has designed many scalable and high-availability networks. Mark can easily be described as the go-to guy for building quality networks and data centers. He is now well-known for his very humorous posts here at The Coffee Desk. This bio has been corrected for our reader Nigles. I hope he feels special now.

More Posts - Website


  1. mr Bill August 30, 2010

    Thanks for this article. I reset my flash settings.

    I agree. Web tracking is sneaky and they know damned well we wouldn’t allow it if we knew about it. That’s why it is hidden from the user.

    Keep fighting the good fight.

    BTW, glad you put that disclaimer in there. I know of a guy that got time for “stalking by proxy” – he posted a comment on Yahoo that listed a guy’s home address and suggested someone be nasty to him.

  2. Few options:
    1) Use an extension (to remove flash cookies or block them)
    2) Use a system tool to removed cookies.
    3) Write a script to delete them on system: Startup, shutdown, browser start up.

    I have a simple script that runs prior to firefox’s launch which deletes the cookies.

    PS: About chaning permissions on the folder to prevent write access to the folders sounds like a good idea at first. What happens when you’re viewing content and that cookie information is needed? Basically I would suggest not using that method.

    Here are my personal suggestions:
    1) Write script that deletes cookies prior to firefox launch. Easy batch file or *.sh script. Just run the script in a short cut and then launch firefox.
    2) Link the script to when you shutdown your PC. That can be done in bash easily and under windows under the scheduler.

    I don’t like the idea of constantly adding extensions to fix abusive advertisers and their tracking mechanisms. The more extensions the slower your browser becomes when launching and surfing the web.

    On a side note; for both windows and *nix; add a folder to your path put your script / batch file in that directory and link to that file on firefox start up and system shut down. Also; you can clean those flash cookies via the command line since it’s in your path; or create a shortcut on your desktop.

    I wonder how funny it would be if people just started to follow around the adobe executives and track their movements and behaviours and posted that information on some web site. Hey, its marketing and you’re sharing your marketing data with your associates. So your associates happen to be every flash user. O’wait that would be an invasion of privacy right… somehow their actions are acceptable in their minds…

    PS: No I am not advocating tracking anyone from adobe or their affiliates. Just making a point… Most people I know don’t like to be tracked and followed and have profiles built upon their persons. They are invading my privacy; within the sanctity of my own home. Lets not forget all the flash security vulerabilites that exist when you use adobe flash. Yes adobe; we are waiting for you to fix your software. Your software invades peoples privacy and puts their PC’s at risk. Your company must have studied quality assure with the MS team.

Leave a Comment

Your email address will not be published. Required fields are marked *