Convert MP4 to MP3
Turn an MP4 video into an MP3 audio file in your browser. The video is discarded and the soundtrack is saved as MP3. Nothing is uploaded.
Your file never leaves your device. How?
Your media is processed in your browser and is not uploaded to our servers for conversion. Page assets (including the converter engine) still load over the network.
Select or drop a video or audio file
MP4, MOV, WebM, MKV, M4A, WAV, FLAC, OGG and more. Converted on your device.
Click, tap, or drop a fileHow to convert MP4 to MP3
Choose the MP4
Drop or select the MP4 video from your device.
Check the quality
MP3 at 192 kbps is preselected. Use 128 kbps for spoken content to get a smaller file.
Convert
Click Convert to MP3. Only the audio is processed, so it is much faster than converting video.
Download
Play the MP3 in the page to check it, then download it.
When MP4 to MP3 makes sense
People usually want the MP3 when only the sound matters: a recorded lecture to listen to on a commute, a talk or podcast that was published as video, a rehearsal recorded on a phone, or a music video they own. An MP3 of a one-hour lecture at 128 kbps is about 58 MB, compared with several hundred megabytes for the video.
The audio inside most MP4 files is already AAC. If your player supports M4A, choosing M4A in the Audio Converter keeps quality slightly higher at the same size. Choose MP3 when the file has to play on anything, including older car stereos and MP3 players.
What happens to your MP4
FFmpeg (compiled to WebAssembly) reads the MP4's first audio track and encodes it with the LAME MP3 encoder at the bitrate you choose. The video track is skipped entirely, which is why this is fast even for long files.
Because the MP4 is read in pieces rather than loaded whole, large phone and camera recordings work. Only the MP3, which is small, is built in memory.
Features
No upload
The conversion runs on your device, so private recordings stay private.
Large MP4s
Videos up to 4 GB and 4 hours on a computer (2 GB and 2 hours on a phone).
Choose the bitrate
128 kbps for speech, 192 kbps for music, 320 kbps for high-quality sources.
Plays everywhere
MP3 works in every player, phone, car stereo and editor.
Frequently asked questions
Is my file uploaded anywhere?
No. The conversion runs in your browser with a WebAssembly build of FFmpeg. Your file is read from your device and the result is saved back to it; nothing is sent to our servers.
Does converting MP4 to MP3 lose quality?
Slightly, because the audio is re-encoded from AAC to MP3. At 192 kbps or higher the difference is not audible for most listeners. For spoken content 128 kbps is indistinguishable.
Can I convert a YouTube link to MP3?
No. The tool converts files already on your device. It does not download videos from YouTube or other sites.
How large a file can I convert?
Files up to 4 GB and 4 hours long on a computer, or 2 GB and 2 hours on a phone. The video is read in pieces rather than loaded into memory, so large recordings work; only the audio file being written has to fit in memory.
Can I keep only part of the audio?
Convert the whole file here, then trim it with the Audio Cutter, or trim the video first with Trim Video.
Does it work on iPhone and Android?
Yes, in Safari, Chrome and other modern mobile browsers. Save the MP3 to Files on iPhone or to Downloads on Android.
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