About Tonera and Our Conversion Method

What Tonera Is

Tonera is a browser-first set of audio, MIDI and sheet-music tools. Its standard audio-to-MIDI workflow runs on your device, so you can convert and adjust a recording without uploading the source file or creating an account.

Models and Processing

Audio transcription uses Spotify Basic Pitch, an open-source polyphonic pitch-transcription model. Tonera decodes supported audio to 22,050 Hz mono, runs the model in the browser, and converts its pitch, onset and contour output into editable notes.

Optional high-precision mode first separates the selected part with HTDemucs through Replicate. This server-side mode is clearly labeled before upload and is the only audio-to-MIDI workflow that sends source audio to a processing provider.

MusicXML-to-MIDI, MIDI preview, WAV synthesis and notation exports are deterministic browser tools and do not use a generative model.

Accuracy and Testing

There is no single accuracy percentage that applies to every recording. Results depend on instrumentation, room noise, compression, reverb and overlapping harmonics. Solo piano, guitar, voice and monophonic leads are the strongest starting points. Full mastered mixes usually benefit from stem separation.

Tonera exposes onset, frame, minimum-note-length and frequency controls so users can inspect and adjust the result instead of receiving an unexplained score. Sample recordings on the converter provide a quick compatibility test before processing personal audio.

Privacy and Retention

Standard conversion stays in the browser. When high-precision separation is enabled, temporary source objects are covered by a one-day Cloudflare R2 lifecycle rule and generated stems by a seven-day lifecycle rule. See the Privacy Policy for full details.

Support

For account, credit or conversion issues, sign in and open a ticket from the Support Tickets area. Include the browser name, input format and the step that failed; do not attach copyrighted or confidential audio unless it is necessary and you have permission to share it.

Tonera's methods, providers and retention details are updated here when the product changes.