Convert MP4 to MP3
To convert MP4 to MP3, drop the video into the converter on this page and click the button; the extracted audio downloads as an MP3. The video is processed by ffmpeg running inside your browser, so the file never leaves your device.
Drop your MP4 here
It becomes a MP3 right in your browser, up to 200 MB
Your file never leaves your device
Why convert MP4 to MP3?
This is the "I only need the sound" conversion: a recorded lecture or webinar to listen to on a commute, a meeting recording headed for transcription, music from a clip, the audio of an interview shot on a phone. Extracting the track turns a file measured in hundreds of megabytes into one measured in tens, playable on any audio device with the screen off. It is also the practical front door to transcription workflows, which want compact audio rather than full video. Because recordings of people talking are sensitive by default, doing the extraction locally instead of uploading the whole video to a converter site is the meaningful difference here.
What is MP4?
MP4 is the default container of modern video: phones record into it, cameras export it, and every browser, TV and editing tool plays it, usually carrying H.264 video and AAC audio. Being a container, an MP4 is really a box around separate video and audio tracks, which is why useful conversions include not just other video formats but also pulling the audio track out on its own.
What is MP3?
MP3 is the audio format that ate the world in the late 1990s, and it remains the most universally supported way to store sound: lossy compression at roughly a tenth of CD size, playable on literally anything with a speaker. Newer codecs like AAC and Opus beat it on quality per kilobyte, but no format comes close to its compatibility across car stereos, ancient MP3 players, browsers, editing software and upload forms.
Quality and what to expect
The audio track inside an MP4 is usually AAC, so producing an MP3 means one lossy re-encode; at the high variable bitrate used here the difference is inaudible for speech and minor for music. The video stream is simply discarded, not converted, which is why even large videos process quickly relative to a full transcode. Length and channel layout are preserved. If the video has multiple audio tracks, the default track is the one extracted. Files up to 200MB are handled in the browser; beyond that, trim the video first or wait for the server engine.
MP4 to MP3 FAQ
Does the video itself get uploaded somewhere?
No. The MP4 is read into the WebAssembly engine inside your browser, the audio is re-encoded locally, and the video data is discarded on your own machine. No request in the network tab carries the file.
How long does extraction take?
Much less than a full video conversion, because the video stream is dropped rather than re-encoded. Expect well under a minute for typical clips; very long recordings scale roughly with their duration.
Will the MP3 quality match the video soundtrack?
Nearly. The soundtrack is already compressed (usually AAC) and is re-encoded once to MP3 at a high bitrate, a step that is inaudible for spoken content and close to it for music. No extra processing is applied.
My video is bigger than 200MB. What now?
The in-browser engine caps at 200MB to stay reliable across devices. Trim the video shorter first, or hold on: a transparent server option for heavy files is on the roadmap, with honest copy about what it means for privacy.