What it is for
A video of a lecture, a sermon, an interview or a family event often only matters for its sound. An MP3 is a fraction of the size, plays in the background on any phone, and is easy to send on WhatsApp or email. This tool takes the sound track out of a file that is already on your device and saves it as an MP3.
It does not download anything from YouTube, Instagram or other websites – only files you choose from your own phone or computer. Please only convert recordings you made or have permission to use.
How to use it
- Choose the file. Most phone videos (MP4 and MOV) and audio files such as M4A and WAV work; your browser reads the sound.
- Optionally type a start and end time, for example 1:30 to 14:05, to keep just the part you need.
- Pick a quality and press Convert to MP3. A bar shows progress; when it finishes the file downloads and a player appears so you can check it.
Which quality?
- 128 kbps is plenty for speech – talks, lessons, voice notes.
- 192 kbps sounds good for most music and is the default.
- 320 kbps is the highest MP3 quality; choose it only if the original was high quality, because MP3 cannot add detail that was not there.
- Mono halves the size and is fine for one person speaking.
Worked example: a 45-minute MP4 of a seminar taken on a phone is 1.2 GB. Trimming it to 2:00–42:00 (40 minutes) and saving at 128 kbps mono gives an MP3 of about 37 MB (40 × 60 seconds × 128,000 bits ÷ 8). That is small enough to email or share in a chat app.
Limits
The whole sound track is held in your device's memory while it converts, so files over 1 GB are refused and very long videos may be slow on older phones. A laptop or desktop handles long recordings best. Keep the page open until it finishes.
Privacy
Nothing is uploaded: the sound is read and encoded by your browser using the open-source LAME MP3 encoder.