11 Free Browser Audio Tools Every Producer Should Bookmark

Every producer ends up with a junk drawer of little needs that have nothing to do with the creative work. You need an acapella out of a song. You need to know what notes a melody is. You need to turn a folder of WAVs into MP3s. You need a tuner right now. And the answer is usually a sketchy download, a paid app, or a website that wants your email.

Here's a cleaner answer: a set of free tools that all live in your browser, where nothing installs and (for the local ones) nothing uploads. Think of it as a utility belt you can pull up in a tab on any machine — laptop, Chromebook, phone. These 11 cover the everyday jobs that come up between the actual beat-making, and they're all part of Onomo. Bookmark the ones you'll keep reaching for.

#The "fix a file" tools

1. Stem Splitter — pull the pieces out of a finished song. The free Quick mode separates a track into vocal and instrumental right in your browser, which is the move when you need an acapella or a clean instrumental. → /toolkit/stem-splitter

2. Converter — change audio formats (MP3, WAV, FLAC, OGG, Opus, M4A), set bitrate, trim, fade, and batch a whole folder at once. Everything happens locally, so nothing is uploaded — perfect for prepping files to share or import. → /toolkit/converter

3. Isolate (Center Isolate / Karaoke) — a quick way to either pull out the centered vocal or strip it for a karaoke/instrumental version, with a keep-vocal option too. Great for fast a-capella or backing-track grabs. → /toolkit/quick/isolate

#The "figure out the music" tools

4. Audio to MIDI — hum or play a part and turn it into MIDI notes you can edit. It has a Melody (single-note) engine and a Polyphonic (chords) engine, a piano roll to clean up the result, and .mid export. Brilliant for transcribing an idea or lifting a melody into your own session. → /toolkit/audio-to-midi

5. Chord Palette — pick a key and mode and instantly see all the chords that belong in it, with voicings, plus MIDI export. The fastest way to find chords that work together when you're writing a progression. → /toolkit/chords

6. Tuner — a chromatic mic tuner with cents readout, an adjustable A4 reference, and a drone to tune by ear. For tuning a guitar, a vocal warmup, or checking a sampled instrument's pitch. → /toolkit/tuner

7. Metronome — tap tempo, time signatures, subdivisions, and it can sync across tabs to your Onomo sessions. For practicing to a click, finding a song's tempo, or keeping a take tight. → /toolkit/metronome

#The "shape the sound" tools

8. Pitch Shifter — change the key of a track without changing its tempo (or vice versa). Essential for matching a sample to your song's key or transposing a part. → /toolkit/quick/pitch-shifter

9. Bass Boost — add weight and low end to a track that sounds thin, especially for phone and earbud playback. A quick fix when something lacks punch. → /toolkit/quick/bass-boost

10. Noise Generator — generate white, pink, or brown noise. Useful as a layer for drum design and risers, for testing speakers, or just for focus while you work. → /toolkit/quick/noise

11. Slowed + Reverb — the dreamy slowed-down-and-washed-in-reverb look in one click. Handy for mood edits, intros, and turning a bright track wistful. → /toolkit/quick/slowed-reverb

#A quick note on what's free vs. what uses credits

Almost everything here is fully free and runs locally in your browser, with nothing uploaded — all the Quick Tools, the Converter, Tuner, Metronome, Chord Palette, Audio to MIDI, and the Stem Splitter's Quick mode. The Stem Splitter also offers an optional Studio AI mode that does cloud-based separation for more stems and cleaner results; that mode uploads your file and uses credits. The free Quick mode covers the everyday vocal/instrumental split with no upload. So you can do the vast majority of your utility work without spending a thing.

#FAQ

Are all of these really free? Yes — the Quick Tools, Converter, Tuner, Metronome, Chord Palette, Audio to MIDI, and the Stem Splitter's Quick mode are free in your browser. Only the optional Studio AI mode in the Stem Splitter uses credits.

Do these upload my audio? The local tools (all Quick Tools, the Converter, and the Stem Splitter's Quick mode) keep your audio on your device — nothing uploaded. The optional Studio AI stem mode is the exception, since cloud separation requires uploading the file.

Do they work on my phone? Yes — these run in a mobile browser, so the whole belt is available on your phone, though larger tasks are comfier on a bigger screen.

Do I need an account to use them? You can use the tools in your browser without installing anything. Some features that save your work to your library will ask you to sign in, but the core utilities work right away.

Which tool gets a vocal out of a song? The Stem Splitter (free Quick mode for a vocal/instrumental split) or the Isolate Quick Tool for a fast center-isolate/karaoke grab.

Can I send these results into a full project? Yes. Audio to MIDI and Chord Palette export .mid you can import, Quick Tool results open straight in Studio, and the Converter prepares files for any of it. The toolkit is built to feed the Studio DAW.