The CDG2MP4 converter is back

Back in 2017 I built a small open-source tool that converted karaoke CDG files into MP4 videos.

The original version uploaded your files to a server, ran ffmpeg, and generated a video. It worked well, but over time the backend became more trouble than it was worth to maintain, so I recently took it offline.

I've finally rebuilt it.

The new version is a Progressive Web App (PWA) powered by ffmpeg.wasm. Everything runs locally in your browser—your files never leave your computer, there's no server to process uploads, and after the first visit it even works offline.

Drop in a karaoke ZIP or matching .cdg and .mp3 files, choose an output quality (up to 1080p), and download the finished MP4.

Screenshot of the new cdg2mp4 app

The first conversion takes a little longer because your browser downloads ffmpeg once. After that, it's cached.

The project is still open source, and because it's now just a PWA, there's very little infrastructure to maintain. It should be a lot easier to keep running for years to come.

Try it at cdg2mp4.com. You can even install it like an app if you use it regularly.

Let me know how it’s working and if there are additional features you’d want! I’ve added PostHog analytics to it, which revealed some early bugs and has helped check traffic.

Current source code available at https://github.com/karaokio/cdg2mp4

The CDG2MP4 converter is down, and I'm rebuilding it

Quick note for everyone who's emailed (and there have been a lot of you): yes, the karaoke CDG2MP4 converter is offline right now. I know. I'm sorry. It was genuinely useful and then one day it wasn't there.

Here's the honest version of what happened. The old tool leaned on a server, a background queue, and Amazon S3 to do its thing. Some hosting issues knocked it over, and keeping that setup alive turned into more babysitting than I had time for. Rather than leave a half-broken tool up, I took it down.

The good news: I'm not just patching the old thing. I'm rebuilding it so this can't happen again.

The new version does the whole conversion **right in your browser**, with no server and no storage in the middle. That means nothing to run up a bill, nothing to fall over, and your files never leave your device. It's the kind of thing that can just keep working for years without me touching it, which is exactly what this tool should have been all along.

The newly redesigned cdg2mp4.com converting a song.

It's close. I'll post again the moment it's live, and it'll be free, like before. Maybe I’ll add some paid tiers for storage and sharing. And I’m also rebuilding the new main Karaokio web app too. More news on that to come…

Thanks for being patient, and thanks for caring about a niche little karaoke tool enough to chase me down about it. Back soon.

Karaokio CDG-2-MP4 Conversion

Current version of app, as of June 27, 2026 is is now a Progressive Web app, completely redesigned.

The information and video below is out-dated to say the least.

An open-source, heroku-hosted web app for converting CDG Zip files to MP4-format video files.

Check it out live here: CDG-2-MP4 Link.

At the time of writing mileage may vary due quota-limit free-tier of queuing service used.

Check out the source here: Github Project Link.