How to Decompress ECM Files (ECM Tools)

Some CD Images are packed in the ECM file format. This can only be read by programs explicitly designed to deal with ECM files. Luckily, there are tools available that allow you to convert these files into much more usable formats such as ISO or Cue/Bin files. This guide shows you how to use ECM Tools to accomplish this conversion.

The reason why some files come in ECM format is because this format compresses the CD image substantially in an effort to not only save disc space, but also bandwidth in the process. That is why some of these files come in ECM formats. Decompressing these files is very straight forward once you have the tools needed. For this guide, we will be using ECM Tools.

First, you need to download ECM Tools which can be located here The RAR archive contains all the files needed to decompress ECM files. (Update May 13, 2020: Old link is now dead, try this).

Find a convenient place on your hard drive for your ECM needs. Next, open the archive and drag and drop the files into this folder. Once done, you’ll have a set of files ready to use. To use ECM tools, find the ECM file in question and drag and drop it over the unecm.exe file. Unecm.exe will automatically open up the ECM file, decompress the file, and close after.

That’s it! You now have a useable CD image that has been decompressed!

Happy computing!

14 thoughts on “How to Decompress ECM Files (ECM Tools)”

  1. This site is great, super helpful. I am encountering plenty of bin/cue files in my search for golden oldies, but I’m curious if I NEED the .cue files at all as a .bin seems to function fine alone.

    Also, how are .iso and .bin files different when emulating?

    Thank you for this site

    1. Thanks for the kind words!

      As a general rule, a .cue file will result in fewer loading errors. If the game runs fine (with music) with just the .bin file, then definitely fly at it. In my experience, some games seem to not load at all without the .cue file though. So, at the very least, it doesn’t hurt.

      The difference between .iso and .cue/.bin file formats should be nothing as far as emulation is concerned. I personally prefer a nice single ISO file though because all the content is stored in one convenient file. I have yet to run into issues when it comes to .ISO formatted discs. .cue/.bin has been problematic for me from time to time – especially when it comes to multiple .bin files. Still, this is from a very limited amount of testing. Currently looking into testing more games to see if all of this holds true for many games or if I just ran into some bad luck early on in the testing stages.

      1. Heya,
        ISO is CUE+BIN packed into one file. BIN contains all data(sometimes expect the .wav files for cd-music) and .cue describes, what data needs to be on which place on the disk. I don’t know why you would fall into a problem with .iso’s… Maybe that was because of cd-music? Who knows..

    1. Copy the file you want to be decompressed. Sent it to the unecm.exe file and paste it in the file. It should be decompressed.

  2. Does anyone remember the name of the compression software people use to use to compress the music files that came with the sega cd’s it would really compress down the music files so that they was so small. I thought it was ecm but when I compressed a ogg files it actually made it bigger.

  3. Stephen Keller

    Directs You to emuparadise which has been shutdown, so this is useless now. Dont waste your time.

  4. Does this work for anime? I want to watch High School of the Dead (anime about a high school with zombies)

    1. Don’t know. I’ve never tried this on anything other than PS1 CD images. Presumably, it would work, but I wouldn’t know how encoding on those images work in the first place.

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