Convert MP4 to MP3 Online
Free, No Upload, Instant
Extract the audio track from any MP4 video and download it as MP3 — entirely in your browser. Preview the waveform, trim if needed, choose your bitrate. Your video never leaves your device.
Drop your MP4 video here
MP4 · MOV · WebM · MKV · AVI — audio extracted locally, video never uploaded
▍What is the sound-goods MP4 to MP3 Converter?
The sound-goods MP4 to MP3 Converter is a free tool that extracts the audio track from any video file and downloads it as a clean MP3 — with no upload, no account, and no waiting for a server. The entire process happens inside your browser using the Web Audio API: your video is decoded locally, the audio stream is isolated, and it is encoded to MP3 using lamejs, an open-source JavaScript encoder.
This is the same conversion that tools like Zamzar, Convertio, CloudConvert, and FreeConvert perform on their servers — but done entirely on your machine. The result is faster, private, and has no file size cap because nothing travels over the network.
▍How to convert MP4 to MP3 — step by step
▍Features
▍sound-goods vs. other MP4 to MP3 converters
| Feature | sound-goods | Convertio | Zamzar | CloudConvert |
|---|---|---|---|---|
| No file upload | ✔ | ✘ | ✘ | ✘ |
| Waveform preview | ✔ | ✘ | ✘ | ✘ |
| Trim before export | ✔ | ✘ | ✘ | ✘ |
| Bitrate selector | ✔ 128/192/320 | ✔ | ✘ | ✔ |
| File size limit (free) | None | 100MB | 50MB | 1GB/day |
| Account required | No | No (basic) | No (basic) | No (basic) |
| Conversion speed | Instant (local) | Depends on server load | Depends on server load | Depends on server load |
▍Which bitrate should you choose?
MP3 bitrate determines how much data is used to represent one second of audio. Higher bitrate = larger file size = better quality. Here is a practical guide:
| Bitrate | File size (3 min) | Best for | Quality |
|---|---|---|---|
| 128 kbps | ~2.8 MB | Voice, podcasts, speech recordings | Good — audible compression on music |
| 192 kbps ★ | ~4.3 MB | Music, general use (recommended) | Transparent for most listeners |
| 320 kbps | ~7 MB | Audiophiles, archival, DJ use | Maximum MP3 quality |
For most use cases — extracting a song from a video, saving a lecture, or converting a Zoom recording — 192 kbps is the right choice. The difference between 192 and 320 kbps is inaudible to most people on consumer headphones and speakers.
▍Common use cases
Extracting a song from a music video
Downloaded a music video in MP4 format and want just the audio? Drop the file in, preview the waveform to confirm it's the right track, and convert at 320 kbps for maximum fidelity. No upload, no watermark, no account required.
Saving a lecture or online course video as audio
Convert recorded lectures, webinars, or course videos to MP3 so you can listen while commuting or exercising. Use 128 kbps for voice content — the file size stays small and quality is more than sufficient for speech.
Extracting audio from a Zoom or Teams recording
Meeting recordings are often saved as MP4. Convert them to MP3 for easier storage, sharing, or transcription. Because no upload occurs, confidential meeting recordings stay entirely on your machine throughout the process.
Creating a podcast episode from a video interview
Recorded an interview on video and want to publish it as a podcast? Convert the MP4 to MP3, use the built-in trim handles to remove the pre-roll and post-roll, and export the clean segment ready for upload to your podcast host.
Archiving home videos as audio
Family videos, events, and concerts recorded on your phone can be converted to MP3 to preserve the audio at a fraction of the storage space. Because the tool runs locally, your private recordings never touch a third-party server.
▍Supported video formats
The converter accepts any video format that your browser's media decoder supports. Compatibility varies slightly by browser:
- MP4 / M4V (H.264 + AAC) — supported in all modern browsers. The most common format for recorded and downloaded video.
- MOV (QuickTime) — supported in Chrome, Edge, and Safari. May not work in Firefox.
- WebM (VP8/VP9 + Opus/Vorbis) — supported in Chrome, Firefox, and Edge. Common for web-recorded video.
- MKV (Matroska) — supported in Chrome and Firefox with standard codecs. May fail if the video uses an uncommon codec.
- AVI — limited browser support. Chrome handles common AVI variants. Use Chrome for best results.
▍Privacy: why no-upload matters for video files
Video files are uniquely sensitive compared to most file types. A single MP4 can contain faces, voices, locations, timestamps, and metadata that identify real people and real events. When you upload a video to a converter website, that data travels to servers in another country, sits in temporary storage, passes through CDN infrastructure, and is subject to that company's data retention and sharing policies — even if they claim "files are deleted within 24 hours."
sound-goods eliminates this entirely. The conversion is performed by your own CPU, in your own browser's memory sandbox, with no network request made for your file. This makes it the correct choice for:
- Private family or personal videos
- Corporate meeting recordings under NDA
- Legal or medical video evidence
- Unreleased content or pre-production footage
- Any video where you cannot guarantee the recipients' data policies
Ready to extract your audio?
Scroll up, drop your video, preview the waveform, and download your MP3 in seconds.
Open the MP4 to MP3 Converter▍Frequently asked questions
Need to merge the converted file with other audio? Try our MP3 Merger — free, no upload, crossfade control. Or trim and cut your audio with the MP3 Cutter.
