CDDA files are normally seen only when audio files have been ripped from an audio CD that uses the CD Digital Audio specification. This is most often done through the Apple iTunes program with the Audio CD burn option.
How to Open a CDDA File
CDDA files can be opened for free with Apple's iTunes on Windows and macOS, and l imagine maybe some other multi-format media players as well.
You can burn audio files to the CDDA format using the File > Burn Playlist to Disc option in iTunes. Just makes sure the playlist you want to burn is the one you're viewing when you select it.
Logic Pro X is another application from Apple that opens CDDA files on Macs but it isn't free. Apple has instructions for burning files to the CDDA format.
While it's probably unlikely to happen since few (if any) formats other than the CD Digital Audio one uses the CDDA extension, it's possible that another program on your computer is associated with this particular extension and will open when you double click on these types of files.
If that happens, and you want to switch it to iTunes, or something else, see our How to Change the Default Program for a Specific File Extension guide for making that change in Windows.
How to Convert a CDDA File
If after converting the CDDA file with CD Ripper, you want it to be in a different format not supported by that software, use one of these free audio converter programs to save the CDDA in MP3 or WAV or in any number of other popular audio formats.
Maybe you want to do the opposite, and convert something like an MP3 file to CDDA so that you can use it in a device that only supports the CDDA format. While this is possible with some file converters, you should understand that the MP3 format uses lossy compression, meaning part of the audio data is trimmed off to reduce the size of the file while still allowing it to sound virtually the same as before.
When you convert MP3 to CDDA, you're not somehow adding that previously removed data back into the file—it's lost forever, even under the CDDA format. It's very much akin to when you zoom in very closely in a photo and can't continue to see more and more detail—that data was never there in the first place.
You cannot usually change a file extension (like the .CDDA file extension) to one that your computer recognizes (like .MP3) and expect the newly renamed file to be usable. An actual file format conversion using one of the methods described above must take place in most cases.
Still Can't Open the File?
If your file doesn't open with iTunes or the other programs mentioned on this page, there's a good chance that you're misreading the file extension. It can be easy to confuse another file format for the CDDA format if the file extensions are similar.
CDA files are one example of where this can happen. CDA files are CD Audio Track Shortcut files and are not related to CDDA files. They may in fact be used with iTunes and other audio players but they're actually just references to audio tracks on a CD. You can't use them like you can a regular audio file.
Another file that can be confused for a CDDA file is a CCD file. These are CloneCD Disc Image files created by CloneCD and used by programs like ImgBurn. They're not at all related to CDDA files and therefore will not open in a CDDA opener.
If your file doesn't actually end with .CDDA, research the file extension it's using to learn more about it and to find which programs can open or convert the file.