Usenet Explained in Plain English

Usenet is a huge, globe-spanning network that is ten years older than the World Wide Web. It remains popular because it has come to function as the fastest and most reliable file-sharing network.

Usenet is similar to the web. For example, to access a web server, you use a web browser such as Internet Explorer or Firefox. To access a Usenet server, you use a Usenet browser like SuperNZB or ezGroups.

In addition to hosting files, Usenet contains discussion groups. These groups pre-date the World Wide Web and have been largely supplanted by web forums.

Some websites are free and some are not. The same is true for Usenet servers, however Usenet servers differ in that they are more expensive to operate because the traffic and data storage is so huge. At the time of this writing in 2011, a full-fledged Usenet server needed to handle about 8 terabytes of traffic per day!

Usenet servers also store files uploaded by users for long periods of time. So, not only is the traffic huge, but so is the storage capacity. When it comes to traffic, some Usenet companies rank in the top-ten, right up there with sites like and

Unlike the web, Usenet doesn’t have a built-in advertising mechanism. So, it’s pretty much impossible for anybody to field a free Usenet server that carries the full compliment of data. Free access to the discussion part of Usenet is available through sites like Google Groups, however you can’t download files. Not even Google can afford to make a free Usenet server available.

How to Access Usenet

Your ISP may make a Usenet server available to you as part of their service. However, many ISPs in the USA no longer do so, so call and ask. If they do not, then you can subscribe to a Usenet service for $8-$25 per month. Even if your ISP does offer a free Usenet server, it will likely run at a slower speed, so you might want to subscribe to a commercial service anyway. Here is a list of Usenet service companies.

Usenet Lingo

Since everything is organized into groups on Usenet, Usenet is often referred to as “the newsgroups”. The term “newsgroups” is used because, back in the day, scientists would post news of their research in the discussion groups. Because of that, Usenet programs are called “news readers” and “news clients”. And that’s a bit confusing because people now also call RSS programs “news readers”. And Usenet service is often called “news service”, even though it has nothing to do with news companies like CNN.

Usenet is like a giant bulletin board where you can read things as well as post things. So, instead of “pages” like you have on the web, Usenet has “posts”. And there are two kinds of posts: text and “binary”. A text post is something you can read. A binary post is everything else: audio, video, software, etc. However, files are not stored in binary format, so you won’t see a series of zeros and ones when you look at a binary post. Rather, you will see encoded text (see the technology section below).


In recent years, the NZB method of accessing Usenet has become popular. There is so much data on Usenet now that just browsing through it is impossible. So, specialized search engines have sprung up to index Usenet just like Google indexes the web. Once you find what you are looking for, these search engines will make an “NZB file” for you to download. Then you plug that file into your NZB program, and it will download the files from Usenet. Take a look at our Learn to Download NZB Files page.

Posting Files to Usenet

Anybody can post files to Usenet. To learn how to do so, download our free NewzToolz program, click the “Newsgroups” tab, and then click the “Post Large Files” button. Click the “Help” button for further information.

Then try to post a small file to the alt.binaries.test newsgroup. You can post anything to this group as it is intended for testing. Once your file is posted, it will show up in the listings of Usenet search engines. However, it may take a few minutes to do so because of propagation.


Usenet is a network without a central server. So, if you post a file to your server, I may not see it on my server until the file “propagates”. That means that your server will call up mine and say: “I have a new file for you.” And my server will say, “OK, send it along.”

But of course, with thousands of servers on Usenet, it’s not that simple. Suffice it to say that Usenet servers talk to each other in such a way that you don’t have to worry about your file making its way to my server. It’s pretty much guaranteed to arrive within a few minutes at most.


When a Usenet server runs out of disk space, it will remove old posts to make room for new ones. How far back it can store posts is called “retention.” With 8 terabytes of traffic per day, you can imagine the vast server farm required by each Usenet server.

So, if you post a file to Usenet, it is not immortal. It will remain on various Usenet servers for various lengths of time depending on the storage capacity of each. Could be a couple of weeks to a couple of years, though the top Usenet companies are always increasing their retention.


Usenet went into operation in 1980, so its technical design is archaic. Back then, it was only capable of handling small text messages, and to this day, everything on Usenet is still stored in small text messages. For example, if you post a large video to Usenet, it will be broken down into scads of little chunks, then “encoded” into text, and posted with a blizzard of small posts to the newsgroup. It’s a pretty ridiculous way to store files, however, in practice it works incredibly well.

Another glaring fault is that there is no built in error-checking. If a small text message gets a bit garbled, you can probably still figure out most of it, or ask the poster to re-send it. In 1980, error-checking wasn’t a big deal, but it is critical for transferring large files. But this problem has been solved by various after-the-fact improvements: yEnc and PAR.

Nevertheless, if you go into a pictures newsgroup and download some pictures, it won’t be long before you get one that is corrupted. It might look funny, or not show up at all. But if you re-download it, you might be able to get a good copy, unless the error occurred while it was being uploaded or propagated. Whenever downloading files, you should get the associated PARs too, if there are any, so that you can fix any errors. If there are no PARs, there may be an SFV file which can tell you if you have a good copy or not, but the SFV can’t fix the file like PARs can.

Just about all large files today are posted with a set of PARs, and newsreaders like SuperNZB will automatically process them for you. So, the process is pretty painless in practice.