Free online ULT to OPUS converter

Source format: ULT

ULT is a tracker module format used by UltraTracker, a DOS-era music tracker. It stores song data such as patterns, instruments, samples, and playback instructions in a compact file designed for computer music composition. ULT files were mainly used by tracker musicians, demo scene creators, and retro game/audio enthusiasts. Typical use cases include preserving old tracker songs, editing legacy module music, and playing back classic DOS tracker compositions in compatible software.

Target format: OPUS

OPUS is a modern audio codec and container format based on the Opus codec, designed for efficient compression of speech and music at very low to high bitrates. It offers excellent quality for its size, low latency, and broad support in modern browsers, media players, and communication tools. OPUS is commonly used for streaming, web audio, voice chat, podcasts, and general-purpose compressed audio distribution.

How to perform the conversion

Because ULT is a tracker module and OPUS is a rendered audio format, the conversion is not a direct file translation. You must first play or render the module to audio, then encode that audio as OPUS. The most reliable workflow is to use a tracker-capable player or converter that can export to WAV, then encode the WAV to OPUS.

1. Open the ULT file in a tracker player or converter. Good desktop options include OpenMPT, XMPlay with module support, or other software that can load legacy tracker modules.
2. Render the module to an uncompressed audio file. In OpenMPT, for example, use File → Export → Wave and save as song.wav. This preserves the full playback output before compression.
3. Encode the WAV file to OPUS. Use a tool such as FFmpeg. A typical command is ffmpeg -i song.wav -c:a libopus -b:a 128k song.opus. You can adjust the bitrate depending on quality and file size needs.
4. Verify the result. Play song.opus in a modern audio player to confirm that the conversion succeeded and that the audio sounds correct.

If you want a simpler no-install workflow, you can convert the file on 101convert.com for free, directly in your browser.

Notes on quality and limitations

ULT to OPUS is a lossy conversion path because the module is first rendered to audio and then compressed again. The original tracker structure, instruments, pattern data, and editability are not preserved in OPUS. If you need to keep the song editable, save or archive the original ULT file as well.

Quality depends on the playback engine used to render the ULT file. Different trackers may interpret effects, mixing, and sample playback slightly differently, so the exported audio can vary between programs. For best results, use a tracker player known for accurate legacy module playback and export at a high-quality WAV setting before encoding to OPUS.

OPUS is excellent for compact distribution, but it is not ideal for archival preservation of tracker music data. For long-term preservation, keep the original ULT alongside the rendered OPUS copy.