NewTry the built-in MIDI Editor

Online MIDI Player, Editor and MIDI to MP3 Converter

The privacy-first MIDI studio. Process files instantly in your browser without uploading to any server.

No Signup Required

No upload • Privacy‑friendly • Works offline (PWA ready)

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What is MIDI Toolbox

What is MIDI Toolbox

MIDI Toolbox is an online suite for MIDI creators: a fast MIDI Player, a powerful in-browser MIDI Editor, and a MIDI → MP3/WAV converter. Everything runs locally in your browser for privacy.

  • Online MIDI Player
    Load and preview MIDI instantly with precise timeline and looping.
  • MIDI Editor (in-browser)
    Edit piano roll, quantize, adjust velocity and export. No install.
  • MIDI to MP3/WAV
    Export high-quality audio with configurable bit rate and normalization.
Core Benefits

Why professionals trust MIDI Toolbox

Experience a studio-grade MIDI environment directly in your browser, designed for privacy, efficiency, and accessibility.

Powered by WebAssembly technology, all processing happens strictly within your browser. Your private MIDI files and audio data are never uploaded to any server, ensuring 100% data security and zero network latency.

Privacy-First Local Processing
Seamless Integrated Workflow
Universal Accessibility

Get started in 3 steps

Start with the Player, edit in the Editor, and export with the Converter.

Key Features

Everything you need for MIDI playback, editing and exporting.

Precise Timeline & Loop

Scrub, set A/B loop points, and practice efficiently.

Piano Roll Editing

Add, move, lengthen notes with snapping and quantize.

Velocity & CC Basics

Adjust velocity and essential MIDI controls quickly.

Instrument Presets

Switch GM instruments and save track settings.

High-quality Export

MP3/WAV export with bitrate, sample rate and fade.

Privacy by Design

Local processing by WebAudio & Tone.js, no uploads.

Stats

Loved by musicians and students

Fast workflow • Clear UI • Reliable exports

Conversions

Unlimited

No daily limits

Toolkit

All-in-One

Player, Editor & Converter

Audio Quality

Studio

Lossless Export

Testimonial

What users say

Creators use MIDI Toolbox to sketch ideas and export tracks quickly.

Indie Producer

Music Creator

Playback, quick edits and MP3 export all in one place. The A/B loop is perfect for practice.

Music Student

Learner

I can slow down, loop difficult bars and tweak notes—right in the browser, no install needed.

Piano Teacher

Educator

My students love the visualizer. It helps them understand note duration and rhythm without getting overwhelmed by sheet music.

Game Dev

Developer

The MIDI to JSON converter is a lifesaver for my web games. Fast, accurate, and runs offline.
FAQ

Frequently Asked Questions

Have another question? Email us any time.

1

Will my files be uploaded?

No. All playback, editing and conversion run locally in your browser for privacy.

2

How to export MP3/WAV?

Open Converter, drop your MIDI, choose bitrate/sample rate/normalization and export.

3

Can I edit MIDI online?

Yes. The in-browser MIDI Editor supports piano roll, quantize and velocity adjustments.

4

Which browsers are supported?

Latest Chrome/Edge/Firefox/Safari. Mobile is partially supported for playback.

5

Is it free?

Yes. Core tools are free to use. Advanced features may be added later.

6

Can I open it in the Player/Editor?

Yes. Tools are linked. You can send files between Player, Editor and Converter.

Create, edit and export MIDI in your browser

Open a tool and start now—no install required.

Online MIDI Editor, Player & Converter - MidiToolbox

MIDI tools in the browser let you play, edit, convert and generate MIDI with zero installs. Our MIDI tools handle tempo, key and channel cleanup, so creators can analyze files, fix issues and export clean results quickly. With WebMIDI support, these MIDI tools keep audio workflows fast, accurate and privacy‑friendly. Use the MIDI tools to practice, arrange and share ideas across DAWs and devices.