Extracting audio from a video takes about 30 seconds in a browser-based tool. Open the MP4 to MP3 converter, drop your video file, and download the MP3. No signup, no watermark, no upload to any server — the conversion runs on your device using FFmpeg compiled to WebAssembly.
Quick answer: Drop your video into the MP4 to MP3 converter and download the MP3. Works for MP4, MOV, MKV, WebM, and most other formats. Processing happens locally — your video never gets uploaded anywhere.
Why extract audio from a video?
The most common reasons:
- A lecture, podcast, or interview recorded as video that you want to listen to on your phone
- A music video where you want the audio as MP3
- A screen recording with voiceover that you want to share as audio only
- Extracting audio before the source gets taken down
- A Zoom or Teams meeting recording you want to send to someone as an audio file
- Reducing a large video to just the audio, which is much smaller
An MP3 from a 200MB video is often under 20MB — a huge size reduction when you only care about the sound.
Which video formats work?
The browser-based converter handles essentially all common video formats:
- MP4 — most common, almost always works
- MOV — iPhone and Mac recordings
- MKV — common for downloaded video, high-quality content
- WebM — browser-captured video, screen recordings
- AVI — older format, still common
- FLV — Flash video, older web content
- WMV — Windows Media Video
For uncommon formats, it's worth trying — FFmpeg handles hundreds of formats and codecs.
Quality settings for MP3 extraction
Bitrate options explained:
- 128 kbps — Decent quality for speech, podcasts, voice recordings. File size is small.
- 192 kbps — Good quality for music and high-quality speech. Good balance.
- 320 kbps — Best quality, largest files. Use for music you care about.
For extracting speech (lectures, meetings, interviews), 128 kbps is perfectly fine. For music, 192–320 kbps is better.
Does extraction reduce audio quality? The video already contains compressed audio. Re-encoding to MP3 adds another compression step. To minimize quality loss, keep the bitrate close to the original audio bitrate — you can't gain quality that wasn't in the original video.
How large will the MP3 be?
Rough estimates for a 1-hour video:
- 128 kbps MP3: ~56MB
- 192 kbps MP3: ~84MB
- 320 kbps MP3: ~140MB
Compared to a 1-hour 1080p MP4 video (~4–8GB), even a 320 kbps MP3 is dramatically smaller.
Using desktop tools for large video files
For videos over 500MB, the browser-based method may be slow depending on your device's RAM. Desktop alternatives:
FFmpeg (free, command line)
ffmpeg -i input.mp4 -q:a 0 -map a output.mp3
This extracts audio at the original quality. The -q:a 0 flag means highest quality VBR MP3.
VLC (free, graphical interface)
- Media → Convert/Save
- Add your video file
- Click Convert/Save
- Choose Audio – MP3 profile
- Set destination file
- Click Start
VLC handles large files well and works offline.
I had a 45-minute webinar recording — a speaker I wanted to revisit on my commute. The video was 1.8GB in MP4. I ran it through the browser converter, set it to 128 kbps (speech quality is fine for a talk), and got a 41MB MP3. It fit easily in my podcast app and I could listen in my car. Took about 4 minutes to process on my laptop.
Extracting audio from specific parts of a video
If you only need audio from part of a video — a specific section, not the whole thing — it's more efficient to trim the video first, then extract audio. This is faster than extracting a full 2-hour audio and then cutting it.
- Use a video trimmer to cut to the section you need
- Then run the trimmed clip through the MP4 to MP3 converter
You get a smaller audio file more efficiently this way.
Converting other audio formats to MP3
If you have audio already (M4A, WAV, OGG, FLAC) and want it as MP3:
- M4A to MP3 — common iPhone voice memos and audio recordings
- WAV to MP3 — uncompressed audio to compressed
- OGG to MP3 — Linux and open-source format to universal MP3
All of these work the same way — browser-based, no upload, no account.
Frequently asked questions
Will the video be deleted or stored anywhere after conversion? No. The conversion happens entirely in your browser — the video file never gets sent to any server. After you close the browser tab, nothing persists. Your original video file stays on your device unchanged.
Is this completely free? Yes — no account, no payment, no watermark. You can use it as many times as you want.
Do my files get uploaded to a server? No. Everything runs directly in your browser using FFmpeg compiled to WebAssembly. Your files never leave your device.