MIDI Toolbox

MIDI Toolbox

Online MIDI Player, in-browser MIDI Editor, and MIDI → MP3/WAV Converter. 100% local processing for privacy.

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MIDI Player

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Drop MIDI file here

or use the Import button in the sidebar

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1x
BPM

The Browser MIDI Player

Free Online MIDI Player — Speed, Loop, BPM Controls

Play any .mid file with studio-grade control — right in your browser. Adjust BPM, loop sections for practice, mute and solo individual tracks, and watch every note dance across a real-time piano roll. No download, no upload, no account.

100%
Local

All parsing and playback happens in your browser. Your MIDI files never leave your device.

30—240
BPM Range

Slow down a difficult passage for practice, or push the tempo up to test arrangements at full speed.

∞
Tracks

Solo, mute or focus on any number of tracks. Built for multi-instrument MIDI files with no track limit.

What you get

Everything a real MIDI player should do

01

Real-time piano roll

Watch every note appear, light up and fade as it plays — across all instruments and tracks, with precise timeline scrubbing.

02

BPM & speed control

Drag tempo from 30 to 240 BPM without changing pitch. Perfect for practicing a tricky passage at half-speed.

03

A-B section looping

Set a loop region to drill the same 4 bars until your fingers know the part. The single most-used practice feature.

04

Per-track solo & mute

Isolate the bass line, mute the drums, focus on one voice in a fugue. Each track gets its own solo/mute toggle.

05

Multiple synth voices

Switch between Synth, AM, FM, Duo and Membrane voices to find a sound that fits the piece you're playing.

06

Zero upload, zero install

No account, no plugin, no desktop app. The file is parsed locally with Tone.js the moment you drop it in.

How it works

From file to playback in under 5 seconds

  1. 01

    Drop a .mid file

    Drag from Finder/Explorer or click to select. The file is parsed instantly in your browser — file name, duration and track count appear immediately.

  2. 02

    Pick a voice, set BPM

    Choose a synth voice from the toolbar. Drag BPM and volume to taste. Defaults work fine for most MIDI files.

  3. 03

    Play, loop, scrub

    Hit play. Enable loop to drill a section. Drag the timeline to skip ahead. Solo or mute tracks as you go.

  4. 04

    Focus tracks

    Toggle solo/mute on individual tracks to isolate a melody line, mute a busy drum part, or compare arrangements.

  5. 05

    Troubleshoot

    No sound? Click anywhere on the page to unlock AudioContext (a browser security requirement). Still nothing? Try Chrome or Edge desktop.

Who it's for

Built for four kinds of MIDI work

Music teachers

Slow down for lessons

Halve the BPM so a student can hear every note in a fast Bach invention, then loop the tricky measures until they're learned.

Students & practicers

Drill any passage

Mute the right hand and play along to the left, or vice versa. Use looping to repeat 4 bars until it's muscle memory.

Producers & composers

Audition arrangements

Hear how a stem sounds in isolation. Solo the bass to check note choices. Quickly preview .mid exports from your DAW before committing.

Hobbyists

Play your old MIDI library

Got a folder of .mid files from the 90s? Drop them in. No need to install Windows Media Player or hunt down a soundfont — it just works.

How it compares

MidiToolbox vs desktop MIDI players

FeatureMidiToolboxWindows MPVLCMidiPlayerX
Install requiredNoYes (Windows only)YesYes (macOS only)
Piano roll viewBuilt-in——Limited
BPM / speed control30—240 BPMFixed0.5—2xYes
Per-track solo & muteYes——Yes
Works on iPad / mobileYesNoLimitedNo
PriceFreeFreeFreePaid

Desktop players are great for power users, but a browser-based player wins for quick previews, lessons, and any computer where you can't install software.

Common questions

Things people ask before they play

If something's wrong

Troubleshooting cheatsheet

No sound at all
Click anywhere on the page first. Browsers require a user gesture before audio can play (AudioContext lock). If still silent, check your system volume and that the page isn't muted in the tab.
Playback is choppy or laggy
Close other tabs using audio or heavy CPU. Try a smaller synth voice (Synth or Duo instead of FM). Very large MIDI files with hundreds of simultaneous notes may stress lower-end devices.
Wrong instrument sounds
This player uses generic synth voices, not General MIDI patches. To hear the original instrument intent (piano, strings, etc.), export with the Converter using a SoundFont, or use the Visualizer for a sound-agnostic preview.
Doesn't work on my phone
iOS Safari has stricter audio rules — tap play after a manual interaction. Some Android browsers limit polyphony. If you're stuck, try the desktop or iPad version of Chrome/Safari.

Under the hood

Technical specs

Audio engine
Tone.js + Web Audio API
MIDI parser
@tonejs/midi
Supported files
.mid, .midi (Type 0 & Type 1)
BPM range
30 — 240
Volume range
-60 to 0 dB
Processing
100% local, no upload

Keep going

Related MIDI tools

MIDI Converter

Render any .mid into MP3 or WAV with a SoundFont. Set bitrate, volume and export — no upload.

Open tool

MIDI Visualizer

Full-screen piano roll visualization for presentations, lessons or just enjoying a piece.

Open tool

MIDI Analyzer

Inspect tempo, time signature, key, instruments and duration of any MIDI file.

Open tool

Privacy & licensing

Parsing and playback are 100% local — your MIDI files stay on your device. You're responsible for ensuring you have the right to play, share or redistribute the files you use.