AUD

Free Online Audio Tools

2 TOOLS

Extract audio from video and trim tracks using your browser’s own codecs. Interview recordings, voice notes and lecture captures are processed on your device — no upload, and no waiting for a queue.

Guides & how-tos

Guides index →

How to get usable audio out of the files you already have — a lecture recording, an interview, a video whose soundtrack you need on its own.

Your browser already has the codecs

Every current browser ships a hardware-accelerated media stack for playing video, and the WebCodecs API exposes it to web pages directly. That means decoding an MP4’s audio track and re-encoding it as MP3 can happen on your machine, at close to native speed, with no server and no multi-hundred-megabyte WebAssembly download.

These tools use that stack through mediabunny rather than shipping a full media framework. The practical result is that a long recording starts processing the moment you drop it in — there is no upload progress bar first, because there is no upload.

Recordings are usually confidential

Audio is often the most personal file people convert. A recorded interview may be under an ethics approval. A therapy session, a client call, a medical dictation or a family voice note is not something to hand to a free web service in exchange for an MP3. Because the work happens locally here, there is no third party in the chain at all — the recording is read from disk into the tab and the output goes straight back to your downloads folder.

File length is limited only by your device’s memory rather than by an upload cap, so a two-hour recording is handled the same way as a two-minute one.

Extracting, trimming and picking a bitrate

Pulling the audio out of a video is a decode-and-re-encode job, not a rename — an MP4 container holds a compressed audio stream that has to be read and written back out on its own. Trimming is different again: cutting a section out and exporting it produces a clean file rather than a player that merely skips part of one.

On bitrate, the useful rule is to match the source. Re-encoding a 128 kbps podcast at 320 kbps does not recover anything; it only makes the file bigger, because the detail was discarded when the original was made. For speech, 96–128 kbps is transparent enough that listeners will not hear the difference; for music, 192 kbps and up is worth the space.

Audio Tools — frequently asked questions

How do I get just the audio out of an MP4 video?

Drop the video into the MP4 to MP3 tool. It decodes the file’s audio track with your browser’s built-in codecs and encodes it as an MP3 — the video track is discarded and the whole job runs on your device.

What bitrate should I choose for a recording?

Match or go below the source. Speech is transparent at 96–128 kbps, music benefits from 192 kbps or higher. Encoding above the original bitrate only inflates the file — the detail was already lost when the source was made.

How long a recording can these tools handle?

As long as your device can hold in memory. There is no upload limit and no queue, so a two-hour lecture starts processing immediately rather than after a transfer.

Is a recorded interview safe to process here?

Yes — it is never transmitted. The file is read into browser memory, processed by your own CPU, and written back out as a download. No third-party service sees it, which is what most research ethics and client-confidentiality rules require.