Free online STM to OPUS converter

Source format: STM

STM is a tracker module format used by early music software, especially Scream Tracker 2. It stores pattern-based music data such as notes, instruments, effects, and playback order rather than recorded audio. STM files were popular in the demoscene and early PC game music production, where compact size and tracker-style composition were important.

Because STM is a sequenced music format, it is typically opened in tracker players or module editors rather than standard audio editors. Common use cases include preserving retro game music, editing old tracker compositions, and converting legacy module files into modern audio formats.

Target format: Opus

Opus is a modern, open, highly efficient audio codec designed for both speech and music. It offers excellent quality at low bitrates, low latency, and broad support in modern players, browsers, and streaming tools. Opus is commonly used for web audio, voice chat, podcasts, streaming, and general-purpose compressed audio distribution.

Compared with tracker modules, Opus is a lossy audio format that stores the final rendered sound rather than editable musical patterns. Its main advantages are small file size, strong quality at low bitrates, and wide compatibility with contemporary software and devices.

How to perform the conversion

Converting STM to Opus is not a direct format translation in the usual sense. An STM file must first be rendered or played back to audio, then encoded to Opus. The best workflow is to use a tracker player or module renderer that can open STM files and export audio, followed by an Opus encoder.

Option 1: Use a tracker player/editor that can export audio

1. Open the STM file in a compatible tracker program such as OpenMPT or another module player/editor that supports STM.
2. Verify that the instruments and effects play correctly.
3. Use File → Export → Wave or a similar render/export command to save the song as .wav.
4. Encode the WAV file to Opus with ffmpeg, for example: ffmpeg -i input.wav -c:a libopus output.opus.

Option 2: Convert directly with a command-line workflow

If your toolchain can decode STM files directly, you can pipe the rendered audio into Opus encoding. In practice, this is usually done with a module-capable decoder or player plus ffmpeg. A common and reliable approach is still to render to WAV first, then encode to Opus.

Using the built-in online converter

You can also convert the file on 101convert.com for free, without installing any software. Upload the STM file, choose Opus as the output format, and download the converted audio file when processing is complete.

Notes on quality, compatibility, or limitations

STM to Opus is a lossy conversion because the original tracker data is turned into rendered audio and then compressed again. This means the result is suitable for listening, sharing, and playback, but not for preserving editability of the original module structure.

Quality depends on the renderer used for the STM file, because different players may interpret tracker effects, mixing, and instrument behavior slightly differently. If exact preservation matters, keep the original STM file as an archive copy and use a high-quality render setting before encoding to Opus.

Also note that some very old STM files may rely on tracker-specific playback quirks. If the output sounds different from the original intent, try a different compatible player or renderer before encoding.