For this conversion

Convert MP4 to MP3: what to know

A recorded lecture, an interview, a voice note someone sent as a video, a clip whose music you want on its own: often only the sound matters. Add your MP4 files above and MP3 is already selected. Toolkitta reads each video in your browser, keeps the audio track, drops the picture and writes a new audio file. The video is never uploaded, there is no account, and the original file is left unchanged.

Detailed guide

Try a video soundtrack conversion

Use the public 12-second practice MP4 linked below the tool. Add it, keep MP3 under Save as and choose 128 kbps in Audio quality. Click Convert 1 file to MP3 and listen to the downloaded result: it should contain about 12 seconds of the quiet tone, with no picture. The moving shapes only exist in the video.

The MP3 is a new lossy encode, so it is not a byte-for-byte extraction of the AAC track. For an excerpt, send the result to Audio Trimmer; use WAV or FLAC as an intermediate if you want to avoid an additional MP3 encode.

How to convert MP4 to MP3

Drop one or more videos into the box above, or tap Choose audio or video. MP4, M4V, MOV, MKV and WebM are accepted, up to 20 files, 500 MB each and 1 GB in total. Each row shows the length of the sound and whether it is mono or stereo. Use the conversion button, whose label shows the file count and output format. Listen to the result on its row, then download each file or all of them as a ZIP.

The conversion streams through the file instead of loading the whole video into memory, which is why large recordings are allowed here while the Trimmer and Merge tools keep a smaller limit. Time depends on the length of the recording and the speed of your device; keep the tab open until the downloads finish.

Choosing the output and bitrate

MP3 plays almost everywhere and is the easiest to share. M4A (AAC) usually sounds a little better than MP3 at the same size and suits Apple devices. WAV saves new 16-bit PCM and FLAC uses lossless compression of encoded PCM. Neither guarantees the original bit depth or source bytes; sizes depend on the sound and format.

The audio inside most MP4 files is already compressed as AAC, so converting it to MP3 or M4A encodes it a second time. Under Audio quality, 192 kbps is the default and a sensible balance for music; 128 kbps is usually enough for speech, and 256 or 320 kbps gives the encoder more room for detailed music. A higher bitrate cannot restore quality the video's own soundtrack never had.

Titles and cover art

When the source file carries descriptive tags, such as a title, artist, album or cover picture, the converter copies them into the new file where the output format supports them. Many phone and screen recordings carry no such tags, so the result may simply be named after the video. You can rename the downloaded file on your device afterwards.

If a video will not convert

The browser has to be able to decode the video's audio codec. AAC and MP3 soundtracks are widely supported; some cameras and editing apps use codecs a browser cannot read, and those rows show an error instead of a result. A file with no sound at all is reported as having no audio track.

Only convert recordings you own or have permission to use. Toolkitta does not download videos from websites or bypass copy protection; it only reads files already on your device.

Questions about MP4 to MP3

Is my video uploaded?: No. The video is read from your device by the browser and the audio file is created there. Encoder code may download from this site the first time a format is used, but your files are never sent.
Can I convert MOV, MKV or WebM too?: Yes. MP4, M4V, MOV, MKV and WebM videos are accepted when your browser can decode their audio codec.
Can I cut the audio after converting?: Yes. Use Send to under a finished file to open it in the Audio Trimmer, select the part you want and save it again.
Does the MP3 keep the full length of the video?: Yes. The whole soundtrack is converted. To keep only part of it, send the result to the Audio Trimmer.

Convert MP4 to MP3