There are dozens of free MIDI converters out there. Most of them are garbage — either they use outdated algorithms, require file upload to sketchy servers, or produce MIDI output that's barely usable.

We tested every free tool we could find and narrowed it down to five that actually work. Whether you need to convert MP3 to MIDI, WAV to MIDI, or any other format, here's how they compare. Here's how they compare.

Quick Picks

  • Best overall: MP3toMIDI — free, no upload, piano roll preview, multi-format
  • Best for notation: MuseScore — free desktop app with sheet music export
  • Best for quick one-offs: Basic Pitch — Spotify's web tool, simple interface

Comparison Table

ToolPricePrivacyFormatsPreviewAccuracy
MP3toMIDIFreeLocal (no upload)9 formatsPiano roll95-98%
Basic PitchFreeUpload requiredMP3, WAV, OGGNone95-98%
MuseScoreFreeLocal (desktop)MP3, WAVSheet music85-92%
KlangioFree / $5 moUpload requiredMP3, WAVYes90-95%
MidiCoFree trialLocal (desktop)MP3, WAVYes88-93%

Detailed Reviews

1. MP3toMIDI — Best Overall

MP3toMIDI interface showing drag-and-drop area and piano roll preview
MP3toMIDI: drag, drop, convert, preview — all in your browser.

MP3toMIDI is the only free tool that checks every box: no file upload, piano roll preview, multi-format support, and solid accuracy. It uses Spotify's Basic Pitch model (the same engine that powers Basic Pitch's web tool) but wraps it in a better experience.

The piano roll preview is the killer feature. You see every detected note before you download, so you know immediately if the transcription is usable. With other free tools, you download a MIDI file, open it in a DAW, and only then discover it's garbage.

Format support is also better than competitors: MP3, WAV, FLAC, OGG, M4A, AAC, AIFF, WMA, and Opus. If you record in lossless formats, you don't need to convert to MP3 first.

Pros: Free, no upload, piano roll preview, 9 audio formats, fast (~12s)

Cons: Large files can be slow on older devices (processing is local)

2. Basic Pitch — Best for Simplicity

Spotify Basic Pitch web interface
Basic Pitch: clean interface, minimal options.

Spotify's Basic Pitch is the AI that made browser-based MIDI conversion mainstream. The web interface is dead simple: upload a file, wait, download. It supports MP3, WAV, and OGG.

The main limitation is that you upload your file to Spotify's servers. For unreleased music, that's a privacy concern. There's also no preview — you download the MIDI blind and hope it's good.

Pros: Free, clean interface, backed by Spotify's research

Cons: Requires upload, no preview, limited format support

3. MuseScore — Best for Sheet Music

MuseScore audio import with notation display
MuseScore converts audio directly into editable sheet music.

MuseScore 4 added audio-to-notation conversion. If your end goal is printed sheet music rather than a MIDI file, this is the best free option. The transcription accuracy is lower than dedicated tools, but you can edit the notation directly in MuseScore's excellent score editor.

Pros: Free, open source, direct notation editing, PDF export

Cons: Slower, lower accuracy, desktop only, limited formats

4. Klangio — Best for Instrument-Specific

Klangio instrument selection interface
Klangio lets you choose the instrument for optimized transcription.

Klangio's differentiator is instrument-specific models. Tell it you're converting a piano piece, and it optimizes for piano frequencies. This helps with accuracy, especially for bass-heavy or treble-heavy instruments.

The free tier limits you to 30-second clips. That's enough for a chorus or verse, but not a full song. The paid plan ($5/month) removes this limit.

Pros: Instrument-specific models, web-based, easy to use

Cons: 30-second limit (free), requires upload, subscription pricing

5. MidiCo — Best for Karaoke Users

MidiCo audio to MIDI interface with karaoke features
MidiCo combines MIDI conversion with karaoke playback.

MidiCo is a desktop app aimed at karaoke enthusiasts. It converts audio to MIDI and can also do the reverse — separate vocals from instrumentals. The MIDI conversion is decent but not as accurate as browser-based AI tools.

Pros: Desktop app, vocal separation, karaoke features

Cons: Free trial limited, Windows only, older AI model

Which One Should You Choose?

For most people, MP3toMIDI is the right starting point. Try it on one song — if the results aren't good enough, then explore the other options.

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Frequently Asked Questions

What is the best free MIDI converter in 2026?

MP3toMIDI is the best free option for most people. It runs in your browser with no file upload, supports 9 audio formats, includes a piano roll preview, and uses the same AI model as Spotify's Basic Pitch. For desktop users who need sheet music output, MuseScore is a solid alternative.

Are free MIDI converters accurate enough?

For single-instrument recordings, yes — free tools achieve 93-98% note accuracy. For complex multi-instrument mixes, you'll need manual cleanup regardless of which tool you use. Paid tools like Melodyne ($99+) only really matter if you need to extract one instrument from a dense mix.

Do I need to install software to convert MIDI?

No. MP3toMIDI and Basic Pitch are browser-based — no installation needed. MuseScore and AnthemScore require desktop installation but are free or affordable.

Is it safe to use online MIDI converters?

It depends on the tool. Server-based converters (like Basic Pitch) upload your file to their servers, which is a privacy concern for unreleased music. Browser-based tools (like MP3toMIDI) process everything locally — your file never leaves your device.

Can I convert MIDI back to MP3?

Yes. MP3toMIDI has a MIDI to MP3 converter that renders your MIDI file to audio. You can also use any DAW to play MIDI through a virtual instrument and export the audio.