How Do Browsers Store Cookies Today, and How Did They Store Them in the Past?

For a simple explanation, think of cookies as small records managed by the browser, not as ordinary files that websites can directly create on your disk. The browser decides how to organize those records internally. Earlier browsers often used a single readable cookie file, while newer browsers commonly use databases, indexes, encryption, and operating-system protections. The exact details differ by browser and operating system.

There’s no universal storage format; each browser chooses its own implementation. Older browsers such as Netscape Navigator commonly stored all cookies in one shared text file, often called cookies.txt—not one separate file per cookie. Tools such as cURL still support that general file format. Modern browsers more often use a database, such as SQLite, and may encrypt cookie values or protect them using the operating system’s secure storage. This makes simply copying the cookie file less useful to attackers, although it doesn’t make cookies completely theft-proof.

The physical layout can vary considerably between browsers and versions. In current browsers, cookies are usually stored alongside other data associated with a website, often in a database or another internal storage system. An important concept here is the “origin”: roughly speaking, it means a particular combination of website address, network protocol, and port. Browser data is separated by origin so that one website normally cannot access another website’s cookies or stored files. Browsers also impose storage limits and may remove older data when space is needed.