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ToolsByUs

Audio Tools

These audio tools run entirely in your browser through the Web Audio API. Your sound file is decoded, edited and re-encoded in this tab — it is never uploaded, and the page's Content-Security-Policy sets connect-src 'self', so the browser itself would block an upload attempt. There is no watermark and no account because there is no server to pay for.

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When should you use a browser-based audio tool?

Audio tools have the same problem video tools do: every free result wants your file first. Upload the voice memo, the interview, the song demo — material that is often personal or unreleased — to a server you do not control, to do work the Web Audio API in your browser does natively and well.

These tools keep the whole job in the tab. The page you load is static HTML and JavaScript; when you drop an audio file, it is decoded into raw samples, edited, and encoded back into a file your browser saves locally. There is no request to inspect and no endpoint to trust — and if you would rather not take that on faith, the Network panel in DevTools settles it in ten seconds.

If you are not sure where to start: Add Music to Video also handles the audio side of video — stripping a soundtrack or replacing it with music of your choice.

Frequently asked questions

How do I know my audio is not being uploaded?

Check rather than trust. Open DevTools, switch to the Network panel, and run any tool here: no request carrying your audio appears. The page is served with a Content-Security-Policy of connect-src 'self' — the browser refuses any request to another origin, so even a compromised script could not send your file anywhere.

Which audio formats are supported?

Anything your browser can decode: MP3, WAV, OGG Vorbis, M4A/AAC and FLAC in most browsers. The tools decode through the Web Audio API and encode back to WAV or a browser-supported compressed format, so the output plays everywhere.

Is there a file size limit or a watermark?

No watermark, ever — there is no paid tier to upsell. Audio is decoded into memory as raw samples, so the practical limit is your device's RAM; the tools state their caps up front and decline gracefully instead of freezing your tab.

Do these tools work offline?

Yes. Load a tool page once and it keeps working with the network disconnected — there is nothing on the other end to talk to. The site is a static export with no API routes, and the editing engine is JavaScript already running in your tab.

What else is on ToolsByUs?

ToolsByUs — Audio Tools