Stop Uploading Voice Memos to "Free" Audio Editors — the Browser Can Do It Locally

Every online "free audio trimmer" I tested wanted my file on their server. For voice memos, interviews, unreleased music — that's a privacy tax nobody priced in.

So we built the audio suite of Toolfyra entirely on the Web Audio API:

• Audio Trimmer — set in/out in seconds, cut, download WAV. Decoding and slicing happen in an AudioBuffer on your device.
• Vocal Remover — classic center-channel extraction: split stereo, invert one channel, sum. Karaoke-style instrumental, zero upload.
• Volume Booster — gain node + soft limiting so you boost quiet recordings without clipping them to death.
• Ringtone Maker — pick 10–30s, auto fade-in/out, export.

The parts that surprised me

1. decodeAudioData handles far more formats than people think (mp3, wav, m4a, ogg depending on the browser codec).
2. WAV encoding is 40 lines of code — write the RIFF header, interleave the float samples. No library needed.
3. Soft limiting (a tanh-style curve via WaveShaper) is the difference between "louder" and "destroyed".

All four tools: free, no account, files never leave the tab. Close the tab = data gone.

Full index: https://toolfyra.com · Sitemap: https://toolfyra.com/sitemap.xml

Disclosure: I built these. Ask me anything about the Web Audio internals — genuinely fun corner of the platform.