MOOD tag does not save to song tags

Is the MOOD tag supported in mp3 files? m4a files are correctly updated with my new MOOD tags but mp3 files, without exception, are not.

see the list in help which fields are supported in which tag version:
(mood is part of the V2.4 specification)

Apparently, Mp3tag supports ID3V2.#. I cannot determine from the documentation if it supports ID3V2.4. Does it?

Yes, it does support id3v2.4

I would say that it is not really important whether MP3tag supports V2.4 (it does) but whether your target player supports it.
E.g. the Windows functions to show tags did not support V2.4 up to now.

I've got the same problem! I'm using Mp3tag v2.91 (from November 30, 2018), and for many other fields with mp3 files, when I change the value of that field, it shows up in Mp3tag. This doesn't happen with the MOOD field (which I assume is actually the TMOO field, as shown at If I change the value of MOOD and save it, it doesn't actually save. Is there a rational reason why this would happen?

How do you know that the mood field does not get saved? (That is: which program does not show it?)
Which tag version do you read, write and delete (TMOO ist a V2.4 field only - no V2.3)?

Thanks for asking! Using Mp3tag v2.91 (as shown in the screenshot below), looking at the song/file "Mamma Mia" by ABBA, you can see that I edited a number of fields on the left, including MOOD. But on the right, you can see that the Mood tag doesn't save, even though all the other fields save. Furthermore, through the Tag field, you can see that the tag is ID3v2.4. Or am I missing something here?

For further clarification, please look at my tag panel setting for MOOD. Am I missing something?

You show us the panel setting but not the colums-setting.
You have to write %mood% in the columns for field (and value) or select the field from the list that MP3Tag offers you in the extended fields-selection. Then MP3Tag will write the correct field for you.

Well look at that! I had %mood% in the column for the field but not for the value. Now that I've corrected for that, it works perfectly. Thank you!