Free online UMX to OPUS converter

Source format: UMX

UMX is a Unreal Music Package file used by older Unreal Engine games, especially titles from the late 1990s and early 2000s. It usually contains tracker-style music data rather than a simple recorded audio stream. UMX files were commonly used in games built with Unreal Engine 1 and related engines, where they served as background music for gameplay, menus, and cutscenes.

Because UMX is a game asset format, it is not widely supported by standard audio players. To use the music outside the game, the file usually needs to be extracted or rendered into a normal audio format first.

Target format: Opus

Opus is a modern, open, highly efficient audio codec designed for speech and music alike. It offers excellent quality at low bitrates, making it a strong choice for streaming, voice chat, web audio, and compact music storage. Opus is commonly stored in an .opus file, often inside an Ogg container.

The main advantages of Opus are small file size, good sound quality, and broad support in modern software and browsers. It is especially useful when you want to preserve audio quality while reducing storage or bandwidth usage.

How to perform the conversion

Converting .umx directly to .opus is usually a two-step process: first extract or render the music from the UMX package, then encode the resulting audio to Opus.

1. Extract or play the UMX file with compatible software. UMX files are game music packages, so a tool that understands Unreal music is needed. Common desktop tools include OpenMPT for tracker/module-style content and Unreal package utilities for game asset extraction. If the file can be opened as a module, export or render it to a standard audio file such as .wav or .flac.
2. Convert the extracted audio to Opus. Once you have a normal audio file, encode it with a tool such as FFmpeg. A typical command is ffmpeg -i input.wav -c:a libopus output.opus. If you prefer a different source format, replace input.wav with input.flac or another supported audio file.
3. Adjust quality if needed. For music, a bitrate around 96k to 160k is often a good starting point. For example: ffmpeg -i input.wav -c:a libopus -b:a 128k output.opus.
4. Verify playback. Test the resulting .opus file in a player that supports Opus, such as VLC, foobar2000, or a modern browser.

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

Notes on quality, compatibility, or limitations

UMX is not a standard audio container, so conversion quality depends on whether the file can be correctly interpreted as the original music data. Some UMX files contain tracker modules that render well, while others may rely on game-specific playback behavior.

Opus is lossy, so the conversion will not be bit-perfect. To preserve the best possible quality, first export the UMX content to a lossless intermediate such as .wav or .flac, then encode to Opus only once. Avoid repeated re-encoding.

Also note that some UMX files may be protected, incomplete, or tied to a specific Unreal game version. In those cases, a direct conversion may fail or produce silence, incorrect instruments, or timing differences.