Yes, no, and maybe.

Yes, deleting cookies will free up room; no, not very much; and only maybe, depending on what you mean by memory.

Clear as mud? Let me explain…

The term “memory” is typically used to refer to your computer’s RAM, or Random Access Memory. That’s the memory that gets erased when you turn off your machine - it’s typically made up of transistors that require power to keep whatever’s stored. When you reboot your machine, for example, most of that process is about loading the operating system into RAM. When you run a program, it is loaded into RAM. Common recommended sizes these days for RAM is anywhere from 128 megabytes (128 million bytes) to a couple of gigabytes (2 billion bytes).

Deleting cookies does not free up RAM. (*).

Sometimes, people will refer to the hard drive as “memory,” but while technically it’s correct - sort of - it’s not really the right term. Most folks refer to the hard drive as, well, the “hard drive,” or “disk drive.” Hard drives are platters of (hard) magnetic media that don’t need power to retain information, though they of course need power to be written to and read from. Typical hard drives range in size these days from 40 to 250 gigabytes (40 to 250 billion bytes).

Cookies are stored on your hard drive. So when you delete cookies, you are freeing up space on your hard drive.

But… cookies are small. Certainly in comparison to your hard drive size, a single cookie might be 100 or 200 bytes. Even cleaning up 1,000 of those only recovers 100,000 bytes, or less than one thousandth of one percent of your hard drive space.

Security and privacy may be reasons to delete cookies, but space isn’t.

(*): OK, technically a browser such as Internet Explorer might use a little memory for each cookie, so fewer cookies might mean that IE might use a little less RAM. Why all the mights? Because it’s not something you can count on… it’s an implementation detail within the browser that could change, or could be handled differently by another browser. Bottom line: don’t worry about it.

For additional related links, see
Will deleting cookies free up room in my computer’s memory? at Ask Leo!.