Introducing: Fenix Mastering – Public Beta 🎚️
I’ve been tinkering away on a lightweight, browser-based mastering tool you can use right on your phone or desktop—no installs, no uploads to a server. It runs locally in your browser with WebAudio.
This started after I saw another guy on Facebook posting a similar thing (with a pretty wild disclaimer at the bottom of his page). This was built from scratch, step-by-step, right here, debugs, features, and all. Maybe if he wasn’t so sensitive about sharing i wouldn’t have bothered 🤔😜

What it does
- Upload MP3/WAV/OGG and master in your browser
- A/B Toggle: Instantly switch between Original and Mastered
- EQ: Bass / Mids / Treble
- Loudness Target with pre-gain normalization
- Limiter with adjustable ceiling
- Fade In/Out for smooth starts and endings
- Presets: Flat, Rock, Metal, Pop, Jazz, EDM
- Stereo Width (simple gain in this build)
- Real-time L/R Meter with clip indicator
- Export: 16-bit WAV, keeps your filename and adds (FenixMastered)
“Beta”?
Yes and it will likely stay that way lol
Credits
Special thanks to Valenta Michal for the inspiration and ChatGPT for rapid bug fixes of Groks code lol
Give it a spin here: fenixstudio.org