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Convert MP4 Video to MP3 Audio

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How to save only the sound from an MP4 video

Extract the soundtrack from an MP4 video and save it as MP3. Adjust the audio bitrate, sample rate and channel setting, and choose whether to remove metadata. The resulting file contains audio only; the video must have an audio track to extract. Use this for a recording you want to listen to, edit or transcribe without carrying the video picture.

Cost: Free to use. File size and usage limits apply.

Extract the audio from an MP4 in five steps

  1. Upload the video

    Click Upload MP4 or drop the videos onto the preview area. Each MP4 can be up to 200 MB, and you can add several at once. The video must contain a sound track; a video without audio can't produce an MP3.

  2. Check which videos are selected

    The list below the preview shows every video that will be converted. MP4s you uploaded or created in other tools on this site sit in Files and are selected as well when the page opens. Open Files and click a video to add it to or remove it from the selection.

  3. Choose the settings

    Audio bitrate starts at 192k (192 kbps). Leave Sample rate on Keep source and Channels on Source unless you have a specific reason to change them. With two or more videos selected, turn on Package as ZIP if you want one archive instead of separate downloads.

  4. Extract

    Click Extract MP3. The picture is discarded and the sound is encoded to MP3 on our server.

  5. Listen and download

    Play the result in the preview player, then click Download. Each video gives its own MP3 named after the video, with its own Download button. With Package as ZIP turned on, you get a single Download ZIP button instead.

Settings and when to change them

Output format and Audio codec are fixed to MP3, so there is nothing to pick there. The settings below apply to every selected video.

Audio bitrate
Seven steps from 64k to 320k, default 192k. The MP3 is encoded at a constant bitrate, so this value and the length of the video set the file size and how much detail survives. As a rule of thumb, 64k to 96k is enough for speech, 128k to 192k suits most music, and 256k or 320k keeps music closest to the source. A bitrate above that of the video's own sound can't add detail; it only makes the file bigger.
Sample rate
Keep source (default) or a fixed rate from 8000 Hz to 48000 Hz. Most MP4s carry 44100 Hz or 48000 Hz audio, which stays unchanged. Higher source rates such as 96000 Hz are converted to 48000 Hz, the MP3 maximum. Lower rates only make sense for speech, and MP3 caps the bitrate there: at 16000 to 24000 Hz the maximum is 160 kbps, at 8000 to 12000 Hz it is 64 kbps, even if you selected more.
Channels
Source (default) keeps mono as mono and stereo as stereo. Surround sound such as 5.1 is mixed down to stereo, because MP3 holds at most two channels. Mono merges left and right into one channel, useful when a voice was recorded on one side only. Stereo always writes two channels; a mono sound track is copied to both sides, which sounds the same. Neither option changes the file size, since the bitrate is fixed; lower the bitrate to get a smaller file.
Package as ZIP
Only appears when two or more videos are selected. On, you get one ZIP archive with all MP3s. Off, every MP3 gets its own Download button.
Strip metadata
Off by default. The MP4's tags, such as title, artist and comment, are then copied into the MP3. Turn it on to remove them, for example before you publish or share the file. Embedded cover art is never carried over.

How big will the MP3 be?

Because the bitrate is constant, the size of the MP3 depends only on the length of the video and the bitrate you choose. The picture quality and the size of the MP4 play no role. Per minute of audio you get roughly 0.5 MB at 64k, 1 MB at 128k, 1.4 MB at 192k and 2.4 MB at 320k.

Example: a 45-minute lecture recording. At the default 192k the MP3 is about 65 MB. For listening to speech, 64k with Channels set to Mono is usually clear enough and brings it down to about 22 MB.

Formats, limits and file handling

Input format
MP4 video (.mp4) with at least one audio track
Output format
MP3 at a constant bitrate, one file per video, named after the video (spaces and special characters become hyphens). Optional ZIP when several videos are selected.
Maximum file size
200 MB per video
Files per job
One or more MP4s, processed one after another in a single job. Every video with a sound track gives its own MP3.
Audio tracks
One per video. If an MP4 contains several, such as two languages, the MP3 uses the track marked as default, which is usually the first one. There is no option to pick another track.
Processing
On our server with FFmpeg and the LAME MP3 encoder. A job stops after 15 minutes. No AI or other external service is involved.
Watermark
None
Storage
Uploads and results are deleted automatically after 48 hours for guests and after 30 days with a free account. Paid plans can keep files longer. Until then, the MP3 also appears under Files in the audio tools, such as Audio Converter and Split Audio.

Frequently asked questions

Is the audio copied or re-encoded?

Always re-encoded, even if the MP4 already carries MP3 audio. Most MP4 videos store their sound as AAC, which the tool decodes and encodes again as MP3. That is a second lossy step, so some detail is lost, and no bitrate can bring back detail the video's sound never had. For music you plan to edit further, choose 256k or 320k.

Why is my MP3 larger than the video?

The MP3 size depends only on duration and bitrate, not on the picture. Videos with little motion, such as screen recordings or slideshows, are often small: if a 30-minute recording is 40 MB, an MP3 at 320k (about 72 MB) is larger. Choose 128k or less, or 64k with Mono for speech.

Why does the job fail with a message about an audio track?

The video has no sound stream, so there is nothing to turn into an MP3. This happens with screen recordings made with audio switched off, clips converted from GIFs and videos that were muted earlier. Check the list below the preview and remove such videos from the selection in Files.

Can I extract audio from MOV, WebM or MKV files?

Not with this tool; it only accepts MP4. Convert the video to MP4 with Video Converter first, then extract the MP3 here. Choosing copy as its Audio codec avoids re-encoding the sound twice when the original audio is AAC, as in most phone videos.

How do I get only part of the audio?

Trim the video to the part you need with Cut Video before extracting. To divide a long MP3 afterwards, for example a lecture into 10-minute pieces, use Split Audio.