Convert MP4 to MP3
Turn MP4 videos into MP3 audio you can play in the car, on any phone or in a podcast app. Conversion takes seconds and happens entirely on your device.
- No upload
- No watermark
- No file size limit
- Hardware accelerated
Drop videos here to convert them
MP4, MOV, WebM, MKV, AVI and more · no size limit or watermark
Processed on your device. Your videos are never uploaded.
Advanced: codec, frame rate, audio, trim
How to convert an MP4 to MP3
- 1
Select your MP4 files
Drop in one MP4 or a batch – recordings, lectures, interviews or music videos you own.
- 2
Keep 192 kbps or lower it
192 kbps is ideal for music. For speech, 128 kbps sounds the same and makes smaller files.
- 3
Convert
MP4 files are read by your browser directly, so only the audio has to be encoded – it is quick even for long videos.
- 4
Download your MP3s
Download each MP3, or get them all in one ZIP.
What happens when you convert MP4 to MP3
An MP4 file usually holds H.264 video and AAC audio. To make an MP3, Asset Compressor reads the audio track, decodes it and encodes it again with an MP3 encoder at the bitrate you choose. The video track is skipped entirely, which is why the conversion is fast and the result is tiny compared with the video.
Because the AAC audio is re-encoded, choose a bitrate at least as high as you need: 192 kbps keeps music transparent for most listeners, 128 kbps is plenty for voices.
MP3 or keep AAC?
MP3 is the most compatible audio format there is: car stereos, old MP3 players, smart speakers, editing apps and every phone play it. AAC (M4A) is slightly more efficient, but some devices and upload forms only accept MP3. If you are not sure, MP3 is the safe choice.
Typical uses
Students convert recorded lectures to listen on the way to class. Podcasters pull the audio from a video interview to edit it. Musicians extract a rehearsal or performance from a phone recording. In each case trimming helps: set a start and end time under Advanced to keep just the part you need.
A one-hour recording at 128 kbps is about 55 MB – small enough to send in most messaging apps.
Other video formats
Have MOV, MKV, WebM or AVI files instead? They convert the same way – see the video to MP3 converter for all formats.
Frequently asked questions
Does MP4 to MP3 conversion lose quality?
Very little at 192 kbps. The MP3 can never sound better than the MP4’s original audio, so choosing a higher bitrate than the source only makes the file larger.
How long does it take?
Usually seconds to a minute, because only the audio is processed and MP4 files are read natively by your browser.
Can I convert a YouTube video to MP3?
No. Asset Compressor doesn’t download from websites – it converts files that are already on your device. Only convert content you have the rights to.
Can I convert several MP4s at once?
Yes. Add as many files as you like; they are converted one after another and can be downloaded as a ZIP.
Related tools
Video to MP3
Save the soundtrack, a podcast recording or a voice memo from any video as an MP3 file that plays everywhere – processed entirely on your device.
Compress video
Shrink MP4, MOV, WebM and MKV files on your own device with hardware-accelerated encoding. Choose a quality level or an exact target size – no upload, no watermark.
Video converter
Change a video’s format in seconds. When the codecs allow it, the streams are copied without re-encoding, so the quality stays exactly the same.
MP4 to WebM
WebM with VP9 or AV1 is built for the web: smaller files at the same visual quality, supported by every modern browser. Convert your MP4s locally.
Related guide
Last updated