Sing or play a line. Get MIDI back.
Warf listens to a single monophonic voice — vocals, guitar, bass, a wind instrument — and converts what it hears into real-time MIDI note events. As a free VST3 plugin for your DAW, or right in your browser, no install required.
From sound wave to note event, in real time.
Warf tracks pitch continuously and turns it into MIDI as you play — or convert an existing recording in one pass.
Real-time pitch tracking
A YIN-based pitch tracker estimates the fundamental frequency of whatever you're playing or singing, continuously.
Clean note on/off
Onset and release debouncing keeps a held note stable and avoids chattering between adjacent pitches.
Legato retriggering
Slide or slur into a new pitch and Warf ends the old note and starts the new one cleanly, no gap needed.
Sensitivity & gate
One sensitivity knob balances speed against false triggers; a noise gate keeps silence from generating notes.
Transpose & MIDI channel
Shift the output up or down by octaves, and route it to any MIDI channel your instrument or track expects.
Velocity from level
Note velocity follows how loud you played, or fix it to a constant value if you'd rather have consistent output.
Monophonic only, and MIDI routing is host-dependent.
One note at a time
Warf tracks a single melodic line — a voice, or one instrument playing single notes. Feed it a chord and it'll report whichever pitch it judges dominant, not the whole chord. This is inherent to the pitch-detection approach, not a bug to fix later.
Check your DAW supports MIDI-out effects
A VST3 plugin that outputs its own MIDI stream from audio needs host support. Cubase, Studio One, Bitwig, and REAPER support routing that output elsewhere. Ableton Live's own "audio to MIDI" is a separate, built-in feature and doesn't apply here.
Install it in your DAW, run it on your desktop, or just open it.
Same pitch-tracking engine every way — the desktop app and the browser version are the exact same PWA, no DAW required for either.
Warf (Beta) — VST3
Installs straight into your system's VST3 folder. Rescan plugins in your DAW afterwards and it'll show up as an effect you can place on an audio track.
Download installer (.exe) Installer blocked by Windows/your browser? Download the raw .vst3 as a .zip instead — unzip it and copy theWarf (Beta).vst3
folder into C:\Program Files\Common Files\VST3\ yourself
Warf for Windows (Desktop)
The browser app in a native window — a Tauri build of the same PWA, so mic capture, recording, file conversion, and Web MIDI all work exactly the same, just without a browser tab.
Download installer (.exe) Prefer an .msi? Download that insteadRun the PWA — any platform
No install, no download. Warf runs entirely in the browser using the Web Audio and Web MIDI APIs, and works offline once loaded.
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Open
warf.monco.io/app.html - Pick a MIDI output (a virtual MIDI port like loopMIDI works well on Windows)
- Web MIDI needs Chrome or Edge — Firefox and Safari don't support it
- Or hit Start Recording instead of Start Listening — stop it and download the take as a .mid file
- Or skip the mic entirely — upload a WAV and download a .mid file, no MIDI output needed
This is a fresh beta. The pitch-tracking engine has an automated test suite covering accuracy against known frequencies and the note-onset/offset logic, but it hasn't been validated against a wide range of real instruments and voices yet. Expect rough edges, and please report anything that sounds wrong via GitHub.