How to convert MIDI to MP4 in your browser (no upload, no install)

The fastest free way to convert MIDI to MP4 is to open midee, drop in a .mid file, pick a theme and resolution, and click Export. The browser renders an H.264 MP4 piano-roll video with audio baked in - locally, no account, no upload, no watermark. A typical 3-minute track finishes in under a minute on any recent laptop.

This guide walks the full MIDI-to-MP4 workflow, explains exactly how the conversion works under the hood, and compares the browser-export route against screen recorders, paid desktop tools, and upload-based converters. If you only want to listen to a MIDI without exporting video, use the online MIDI player instead.

What does "MIDI to MP4" actually mean?

A MIDI file stores musical performance data - note pitches, velocities, timing, tempo, and control changes - but no audio and no video. To share that performance on YouTube, TikTok, Instagram, or Discord, you need to render it into a format every player understands: an MP4 with audio you can hear and a piano roll you can watch. That render is the "MIDI to MP4" conversion.

It is fundamentally different from "MIDI to MP3," which produces only audio. MP4 is the right format when you want viewers to see the notes move.

How do I convert a MIDI file to MP4 for free?

1. Open midee in Chrome 94+, Edge, Safari 16.4+, or Firefox 130+. Video export needs a browser with a built-in video encoder, which these all have.
2. Drag any .mid or .midi file onto the page, or click to browse.
3. Press play to preview the piano-roll visualization in real-time.
4. Pick a theme (Dark, Midnight, Neon, Sunset, Ocean), an instrument, and a particle style.
5. Click Export in the top-right toolbar.
6. Choose a preset: 720p, 1080p, vertical 9:16, square 1:1, or your native canvas size.
7. Click Start - the MP4 saves to your Downloads folder when rendering finishes.

That is the entire workflow. Your MIDI file, the rendered audio, every video frame, and the final MP4 stay on your device the whole time. There is no upload, no signup, no paid tier, no watermark.

How the MIDI to MP4 converter works

midee does the whole conversion inside your browser tab using the browser's built-in video encoder, the same one video-call apps use. There is no server, no upload, and no FFmpeg download.

• Audio is rendered from the MIDI with a sampled instrument at 44.1 kHz and encoded to AAC at 192 kbps, the format every video platform accepts.
• Video is drawn frame by frame from the piano roll at your chosen resolution and encoded to H.264 at 30 fps and 8 Mbps by default. Hardware encoding is used whenever your machine offers it.
• The MP4 is assembled with the index at the front, so it streams immediately in browsers and uploads cleanly to YouTube, TikTok, and Instagram.

Because frames are generated from the MIDI clock rather than captured from the screen, there are no dropped frames and the audio stays locked to the visuals. If a browser lacks the encoder, midee shows a clear error rather than writing a broken file.

If you are curious about the engineering, read why I replaced ffmpeg.wasm with WebCodecs.

What resolution should I export?

Match the export resolution to where the video will live. midee defaults to 1080p - it's the safest landscape choice on every major platform - but short-form feeds require 9:16.

A 3-minute MIDI at 1080p / 30 fps with hardware-accelerated H.264 typically finishes in 30–60 seconds on a recent laptop. The same MIDI at 4K can take 3–5× longer because the encoder is moving roughly 4× the pixels per frame.

MIDI to MP4 vs MIDI to MP3 - which one do you want?

• MP4 when you want viewers to see the performance - a piano-roll video that scrolls while it plays. This is what social platforms reward; nobody watches a static waveform on TikTok.
• MP3 or WAV when you only need audio - a SoundCloud upload, a podcast bed, or background music. The export dialog's Audio tab skips the entire video pass and writes a 192 kbps MP3 or a lossless 16-bit WAV. It is far faster than MP4 export because no frames need to be rendered.

If you need both, run the video and audio exports separately. They come from the same offline render, so the audio matches exactly. The MIDI converter page compares every output format.

Why not just screen-record Synthesia or MIDIano?

Screen recording works, but it stacks tools and failure modes. You set up Synthesia (or MIDIano, or Piano from Above), launch OBS or QuickTime, capture, trim the silence at the start and end, verify the audio is in sync, and re-render if it isn't. A single dropped frame from the recorder produces a visible stutter that cannot be fixed in post. Audio passes through your system mixer, which can clip or pick the wrong device.

The browser-export route sidesteps all of that. Nothing is captured in real time, so there are no dropped frames, and the audio and video come from the same render, so they cannot drift apart.

That said: if you want cinematic camera moves, slow-motion freezes, hand-animated flourishes, or multi-MIDI medleys, a desktop tool like SeeMusic will still produce more polished output. midee is optimized for "drop in MIDI, get a clean MP4 in a minute" - not for color-graded music videos.

MIDI-to-MP4 workflows compared

For most musicians, the browser-export workflow eliminates four out of the five typical steps.

When midee is the wrong choice

A useful list - the limits are real and worth knowing before you invest time:

• Very long MIDIs on weak hardware. A 30-minute track at 4K on a low-power tablet will take a long time. Drop to 720p or move to a laptop.
• Custom motion graphics or lyric tracks. midee renders one piano roll per export. Multi-layer compositing belongs in After Effects, DaVinci Resolve, or Premiere.
• MusicXML / sheet-music export. midee renders a piano-roll view, not notation. Render the MP4 here and the score in MuseScore or Noteflight if you want both.
• Older browsers. Firefox 129 and earlier cannot encode video. midee shows a clear error rather than producing a broken file. Update the browser or switch to Chrome.

Common questions

Is midee really free for MIDI-to-MP4 conversion? Yes. midee is open source, runs entirely in your browser, and has no paid tier, watermark, or signup.

Does midee upload my MIDI file to a server? No. Parsing, audio rendering, video encoding, and MP4 muxing all happen locally in your browser tab. Network traffic during export is zero - you can disconnect from the internet and the export will still finish.

Will the exported MP4 include audio? Yes. midee renders your chosen instrument offline at 44.1 kHz, encodes it to AAC-LC at 192 kbps, and muxes it into the MP4 alongside the video. The file is ready to upload directly.

Can I export 4K MIDI videos? Yes, on hardware that supports 4K H.264 encoding. midee checks what your browser can encode and picks the highest option. Recent M-series Macs and current Intel and AMD machines handle 4K at 30 fps comfortably.

Can I make vertical MIDI videos for TikTok, Reels, or Shorts? Yes. Pick the vertical 9:16 preset for a 1080 × 1920 MP4 ready for short-form feeds.

What file size should I expect? At the default 8 Mbps video bitrate, expect roughly 1 MB per second of video - about 180 MB for a 3-minute MP4 at 1080p. The audio track adds ~1.5 MB per minute. 720p exports are typically half the file size; 4K is about four times larger.

Can I use copyrighted MIDI files? midee will open any standard MIDI file. Copyright and platform terms are between you and the rights holders; midee does not filter content.

Does midee work offline? The export itself makes no network requests. You need a connection to load the app and the instrument's sample set; once those are in, you can disconnect and the MIDI-to-MP4 pipeline still completes, because it runs entirely client-side.

Try it

Open midee in your browser, drag in a .mid file, preview the piano-roll visualization, and export an MP4. Start with 1080p for YouTube and landscape players, or Vertical for Shorts, TikTok, and Reels. The render runs in your tab while you do something else - no upload, no install, no waiting on a server queue.

If you also want to see midee compared against other MIDI tools, read the Synthesia alternative writeup or browse the best MIDI visualizers shortlist. To go deeper on piano-roll video specifically, see the piano-roll video maker page.