yEnc Explained in Plain English

yEnc is an encoding method for posting files to Usenet newsgroups. If you click on a yEnc-encoded post in your newsreader program, and all that you see is gobbledygook, then you need to upgrade your software. yEnc has been a standard for many years now, so if your newsreader client doesn’t support it, it probably never will. ezGroups is a good place to start. Not only does it have yEnc built-in, but RAR and PAR also, which are additional new standards.

If you limp along with an old newsreader, you can’t even imagine the amount of content that you are missing on Usenet these days. In addition to yEnc, RAR, and PAR, there is also the NZB revolution. ezNZB will walk you through the process step-by-step.

yEnc was invented to increase efficiency. Initially, it created a lot of hostility because it was not supported in Outlook Express, and Microsoft never did implement it. Consequently, Outlook users who used to be able to just click on a JPEG and see a picture were all of a sudden seeing gobbledygook. And they got angry. After all, very few people enjoy upgrading their software.

yEnc was needed to improve the compression of data as larger-and-larger files were posted to newsgroups. Usenet posts can only contain text, so pictures, movies, sounds, and any other files, must first be converted to text before they can be posted. Today, files are first compressed with RAR, encoded with yEnc, uploaded to Usenet with a set of PAR files, and an NZB file. That’s the standard now.

yEnc is not a file format. It is only a temporary format for when the file in question is residing in a newsgroup. yEnc exists only because of the historical artifact of Usenet servers storing all their data as text. You will probably never come across a yEnc file away from Usenet.

Question: I have a Mac. Is there anything special that I need to know?

No, yEnc works the same way on Mac and Windows. You just need a Usenet client program that supports it, like ezGroups.

Question: I already downloaded a bunch of yEnc-encoded posts. Can I decode them?

Yes you can with NewzToolz.

Question: My newsreader supports yEnc, but many of the files come out bad. What is the problem?

There were a lot of buggy yEnc-posting programs in the past. Here are some:

  • NNTP Power Post 2000 (Build 25b; yEnc)
  • NNTP Power Post 2000 (Build 24c)
  • yPost / 0.45
  • MT Newswatcher 3.2

If you find somebody posting bad yEnc files, you should email them and tell them to switch to NewzToolz.

2 Responses to “yEnc Explained in Plain English”

  1. Skipping Bullett says:

    The decoding of yENC seems to require all the pieces to be together and in the proper order to recreate the whole and it is my experience it is difficult to do this since all the files are received in a jumble and many are incomplete. You cant just put them all in a pile then decode them unless the program you use is able to sort out the good from the bad the complete from the partial. AND should also be able to deal with MIME and UUCODE and HQX and BASE 64 and not just yENC. You really need sorting ability and confirmation abilities to verify all is in order. I don’t see such a thing anywhere in the news communities.

    • Matt says:

      Really? yEnc is a VERY widely-used standard. All of our apps use it, and they work perfectly. This has been the case for many years.

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