Free online ULT to M4A converter

Source format: ULT

ULT is a tracker module format used by UltraTracker and related music software. It stores song data such as patterns, instruments, samples, and playback instructions rather than a finished audio stream. ULT files were popular in the demoscene and among tracker musicians because they are compact, editable, and preserve the structure of a composition for later remixing or playback in compatible players.

Target format: M4A

M4A is an audio container commonly used for AAC or sometimes ALAC encoded audio. It is widely supported by phones, media players, and streaming devices, and it is a good choice for distributing finished music because it offers efficient compression and broad compatibility. Unlike ULT, M4A is a rendered audio file, so it contains the actual sound output of the module rather than the editable tracker data.

How to perform the conversion

Because ULT is a tracker module, the conversion is usually a two-step process: play or render the module to audio, then encode that audio as M4A. The most reliable approach is to use a tracker player or module renderer that can open ULT files, followed by an audio encoder such as FFmpeg.

1. Open the .ult file in a compatible tracker player or module renderer. If you use a tracker application, look for File → Open and load the module.
2. Render or export the playback to a lossless audio file such as .wav or .flac. Many players and trackers offer File → Export, Render, or Save as WAV.
3. Convert the rendered audio to M4A with FFmpeg. For example, if you exported song.wav, run:
   ffmpeg -i song.wav -c:a aac -b:a 192k song.m4a
4. If your tracker can export directly to a compressed format, you can still use the same principle: first ensure the module is rendered correctly, then encode to .m4a.

If you want a simple browser-based workflow, you can convert the file on 101convert.com for free without installing any software.

Notes on quality and limitations

ULT to M4A is not a direct format-to-format conversion in the same sense as converting one audio file to another. ULT contains sequenced music data, so the final sound depends on the player, sample interpolation, loop handling, and effect interpretation used during rendering. Different trackers or renderers may produce slightly different results.

For best quality, render the module to a lossless intermediate such as WAV before encoding to M4A. This avoids compounding compression artifacts. Also note that once converted to M4A, the file is no longer editable as a tracker module; the pattern and instrument structure are flattened into audio.