How to master a track in your browser
- Drop your final mix (MP3, WAV, FLAC…) — it is decoded on your device, never uploaded.
- Pick a genre target and hit Analyze & build my chain, or drop a reference track to match its tonal balance.
- Press Play and shape the sound live: rebalance stems, revive transients, EQ, bass control, exciter, width, glue and maximizer — flip A/B anytime to compare with the original.
- Render, check the LUFS readout and the MP3 codec preview, then export WAV (16-bit dithered or 32-float) or MP3 320.
Mastering Studio chains the tools a mastering engineer actually reaches for into one signal path, in the right order, with a live spectrum and limiter-reduction metering so you can hear and see every decision. The assistant gives you a competent starting point in seconds; every fader stays yours afterwards. Because the whole suite runs on the Web Audio API, it works on any laptop without installs, accounts or rendering queues — useful for self-releasing artists, podcasters tightening an episode, and producers who want a fast, free second opinion on their own master.
Wear headphones or trust monitors you know: mastering decisions made on laptop speakers rarely survive the car test. The codec preview helps too — hearing your master through MP3 at 128 kbps before release beats finding out from a listener.
FAQ
How do I master a song online for free?
Drop your final mix into the Mastering Studio, pick a genre target and press Analyze — the assistant measures loudness and tone, then sets up the EQ, bass control, glue compressor and maximizer for you. Audition the chain live, tweak any module, then render and export MP3 or WAV. Everything runs in your browser, free, with no upload.
Can I really adjust vocals or drums inside a finished mix?
Yes — the Stem Rebalance module separates the stereo file into bass, vocals, drums and other instruments using frequency and transient analysis, then lets you raise or lower each part before the rest of the chain. It is an honest approximation rather than studio-grade neural separation, but a couple of dB of correction works remarkably well on most mixes.
What loudness should my master hit for Spotify or YouTube?
Streaming services normalize playback to roughly -14 LUFS, so the Pop/Streaming target aims there, while club-oriented genres often master louder. The maximizer shows your measured LUFS after every render so you can hit a target deliberately instead of guessing.
Is this mastering tool really free, and is my track uploaded?
Completely free — no signup, no watermark, no track limit. Your audio is processed entirely on your own device with the Web Audio API; nothing is uploaded to any server, which also means there is no queue and no file-size cap beyond your device's memory.
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