BELLOWS
The facts below are what the maker publishes about BELLOWS, checked and dated. Our editors have not written about it yet.
Plans and prices
From BELLOWS's own pricing page, checked 12 Oct 2026.
| Plan | Price | What it gives you |
|---|---|---|
| BELLOWS | Free | Free, open source audio engine |
The facts
Each one read from BELLOWS's own pages, with the date it was checked.
What it does
- Audio engine
- The library uses an AudioWorklet kernel that schedules events on the audio thread for sample-accurate timing.checked 12 Oct 2026
- Built-in instruments
- The site says BELLOWS includes 18 built-in synthesizers and supports playing with a mouse, keyboard, or MIDI controller.checked 12 Oct 2026
- Commercial use
- Yeschecked 22 Sep 2026
- Formats and MIDI
- The library supports WAV encoding and decoding, standard MIDI file read and write, Web MIDI where available, and WebCodecs Opus export where available.checked 12 Oct 2026
- Generative music
- A seed word can generate beats, basslines, melodies, and chords, with the same seed producing the same song each time.checked 12 Oct 2026
- Import sounds
- Users can load SoundFont files or their own audio samples and play them across a keyboard.checked 12 Oct 2026
- License
- The project is released under the Apache-2.0 license.checked 12 Oct 2026
- Music theory
- The library supports more than 30 scales, chord parsing, voice leading, negative harmony, and tunings including EDO and just intonation.checked 12 Oct 2026
- Offline rendering
- The engine can run in Node without a browser to render songs to WAV files.checked 12 Oct 2026
- Product
- BELLOWS is a free, open source audio engine and interactive browser instrument and workbench.checked 12 Oct 2026
- Recording
- The browser workbench can record music to a WAV file, and the site says it requires no account or upload.checked 12 Oct 2026
- Sound tools
- The engine includes synthesizers, drum machines, samplers, soundfont support, sequencing, and effects.checked 12 Oct 2026
- Use in projects
- The library can be installed with npm, loaded from unpkg or jsDelivr, or imported into apps built with Vite or webpack.checked 12 Oct 2026
Where it runs
- Browser requirements
- AudioWorklet is required; the repository lists Chrome 66+, Firefox 76+, and Safari 14.1+ as supported, while Web MIDI is limited to Chromium and Firefox.checked 12 Oct 2026
- Supported platforms
- webchecked 22 Sep 2026
Money
- Free plan
- Yeschecked 22 Sep 2026
The company
- Maker
- The site identifies Moheeb Zara (@virgilvox), hack.build, as the maker.checked 12 Oct 2026
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