Drop MIDI files here to convert to JSON
or
For best performance, limit to 20 files (max 100MB total)
No files selected
Batch Processing
0/0
Professional MIDI to JSON Converter for Tone.js & Web Audio Developers
or
For best performance, limit to 20 files (max 100MB total)
No files selected
Convert multiple MIDI files simultaneously with our powerful batch processing engine. Save hours of tedious work by uploading your entire collection at once, letting MidiEasy handle everything from small projects to extensive libraries.
Experience industry-leading conversion speeds that won't keep you waiting. Our optimized algorithms process your MIDI files instantly, delivering high-quality JSON output in seconds, not minutes—perfect for developers who value efficiency.
Your musical creations remain yours alone. Our MIDI to JSON converter online processes all conversions directly in your browser—we never upload, store, or access your MIDI files on any server. Work confidently knowing your intellectual property is completely secure.
Converting your MIDI to JSON file is simple and straightforward with our free online three-step process.
Drag and drop your MIDI files into our converter online or use the file selector. We support batch MIDI to JSON uploads to handle multiple files at once.
Click "Convert MIDI" and our parser instantly transforms your MIDI data into structured JSON format, preserving all musical information with perfect accuracy.
Get your Tone.js-compatible JSON from MIDI files individually or download everything as a ZIP archive. Ready to use in your web audio projects immediately.
No registration, no installation—just a simple, fast, and free MIDI to JSON converter online for all your musical needs.
MIDI to JSON helps creators at every level transform their MIDI files into web-ready JSON for seamless Tone.js integration.
Easily integrate musical elements into your web applications without the complexity of audio processing or format conversion.
Bring your game soundtracks and interactive audio elements to life in browser-based environments with simple implementation.
Take your compositions from your DAW to the web with a format that preserves timing, notes, and expression for online playback.
Create responsive audio installations and web experiences that react to user input with professional-quality music playback.
Find answers to common questions about our MIDI-to-Tone.js-friendly JSON conversion service.
Yes, we recommend keeping the total upload size under 100MB, with individual MIDI files not exceeding 10MB, and no more than 20 files per batch processing. These limits help ensure optimal conversion performance and user experience.
Yes, we support batch conversion. You can drag and drop or upload up to 20 MIDI files at once. After processing, you can choose to download files individually or as a single ZIP package.
Converted JSON from MIDI files are not stored on any server. All conversions happen directly in your browser. The entire MIDI to JSON online free conversion process takes place on your computer, ensuring user data privacy and security. Conversion results exist only in your browser session and disappear when you close the page.
If you encounter errors during conversion, the website will display specific error messages. For individual file errors during batch processing, you can click the "Retry" button to attempt converting that file again. If it still fails, you can refresh the page and try again, or check if your MIDI file is valid.
We support standard MIDI file formats (.mid and .midi extensions), including MIDI 1.0 format. We can parse both Format 0 and Format 1 MIDI files, preserving all MIDI data including note events, control changes, instrument settings, rhythm, and tempo information. The converted JSON format is specifically designed for integration with Tone.js and the Web Audio API, ensuring high-quality music playback and interaction in web applications.
Explore our latest articles about MIDI to JSON conversion and web audio development