What are local shared objects?

Local shared objects, sometimes referred to as "Flash cookies," are data files that can be created on your computer by the sites you visit. Shared objects are most often used to enhance your web-browsing experience. A website can write a cookie on your computer, and the next time you visit it will load that cookie and its information in a way that provides a more customized experience. For example, you may have asked a site to remember your login name. That information is stored in the cookie and retrieved on your next visit so that the website displays your name in the login field on the site.

A local shared object is exactly like a browser cookie, except that it can also store data more complex than simple text. Shared objects, by themselves, can't do anything to or with the data on your computer. More importantly, shared objects cannot access or remember your e-mail address or other personal information unless you willingly provide such information. Responsible websites use this feature to provide a better user experience; however, you can use Adobe® Flash® Player security settings to control the degree to which local shared objects work.

You can control the storage of local shared objects through the Flash Player Settings Manager, which lets you choose a comfortable level of privacy protection that Flash Player will maintain as you browse the web. This includes disabling the storage of shared objects for individual websites, or completely disabling the storage of shared objects altogether.

How do local shared objects work?

A local shared object can be read only by the website domain that created the object. For example, if you asked www.[siteA].com to store your login name, it might use Flash Player to write a local shared object that contains the login name information. That local shared object can only be read by www.[siteA].com; it cannot be read by www.[siteB].com, or even a different address location2.[siteA].com.

Local shared objects, which are stored on your computer by websites you visit, can only be read by the site that creates them.

How do I disable local shared objects?

Adobe Flash Player provides a number of ways you can manage a website's ability to store information in Flash Player local shared objects through the Settings menu, which is accessible by right-clicking Flash content, and the Settings Manager. By default, Flash Player allows each site to store only 100KB of data in a local shared object on your computer. If a site needs more than that, you will see a dialog box requesting that you allow more space. You can control storage for individual websites or for all websites by changing Flash Player settings. Flash Player also allows you to delete data that may be stored. For more information on how to manage your local content settings, see the TechNote: How to manage and delete your local shared objects.

Conclusion

Local shared objects are useful for allowing Flash developers and websites to create richer and more personalized user experiences. In addition, most responsible sites have privacy policies, which you should review to understand if and how the site uses your information. The amount of information you are willing to share with your favorite websites, Internet marketers, or advertisers is a personal decision, and you should set your browser and Flash Player settings accordingly.

Other resources

• TechNote: How to manage and delete local shared objects
• Tech Note: How to disable third-party local shared objects

Adobe takes consumers' privacy seriously and is committed to protecting the security of individuals' personal information on the web. We are dedicated to helping you maintain a more secure browsing experience by providing and continuously improving Flash Player privacy controls.