Convert MP4 to MP3
Save just the sound of a video as MP3 — listen to recorded lectures or interviews in an audio player. The video never leaves your browser.
Settings
How to use
- 1
Add audio or video
MP3, WAV, M4A, FLAC and other audio files, or video files such as MP4 and MOV to extract the audio from.
- 2
Choose format and bitrate
Pick MP3, M4A, WAV, AAC, OGG, OPUS, FLAC or AIFF. You can also downmix to mono or change the sample rate.
- 3
Convert and save
Press Run. Multiple files are processed in turn and can be saved together as a ZIP.
How the audio is extracted
Only the audio track inside the MP4 (usually AAC) is read; the video stream is skipped. A two-hour video takes a few minutes and almost no memory.
Because MP4 audio is usually AAC, converting to MP3 is a lossy-to-lossy conversion. To avoid any loss, use “Extract audio from video” and choose M4A, which copies the AAC without re-encoding.
Frequently asked questions
Is the video sent to a server?
No. Reading the video and writing the audio both happen in your browser. Processing statistics used to fix bugs (device specs, error types and so on; never the video itself or its file name) are sent to this site's server. You can turn this off with the switch under “Help us improve the service” at the bottom of the page.
Do long videos work?
Yes. The video stream is skipped and the audio is streamed, so videos of several hours are fine.
Is there a lossless option?
Yes. In “Extract audio from video”, choose M4A to copy the AAC audio from the MP4 as-is. This page converts to MP3, which re-encodes and loses a little quality.
Which bitrate?
128 kbps for speech, 192 kbps or more for music. A bitrate higher than the source does not improve quality.
Help us improve the service
If a conversion fails, sending us the circumstances helps us track down the cause. Knowing which devices and formats fail most often, and how long processing takes, lets us revise the supported formats and fix the bugs behind them. If you don't mind, leaving this on is a real help.
What is sent
- The tool you used and the settings you chose (output format, quality, etc.)
- Your device specs (GPU, memory, core count)
- The input format with a rough size
- How many files succeeded or failed and how long it took
- The error type and details when something fails
What is never sent
- The files themselves and file names
- Text, subtitles or prompts you add to a video
- The text to be read aloud, voice descriptions, the pronunciation dictionary and saved voices
- The text in PDFs, the text you rewrote or redacted, passwords, font names and the page ranges you enter
- IP addresses
The data goes only to this site's own server, never to a third-party service.
Details sent by specific tools (counts, times, kinds and yes/no only)
In addition to “What is sent”, text to speech and the PDF tools send the following details.
- Text to speech
- The approximate number of characters and sentences, how many parts the text was generated in, and how long the AI model took to load.
- PDF tools (all)
- The page count range, whether editing is restricted, whether a permissions password was entered, and whether the PDF is signed or encrypted.
- PDF text editing and redaction
- The numbers of rewrites, deletions, white-outs and redactions, the number of rewritten characters by source (original font or fallback font, the latter as a range) and the fallback typeface, the kinds of reasons why lines cannot be edited, and the number of pages turned into images by redaction and the reasons.
- PDF page operations and conversion between images and PDF
- The numbers of inputs and outputs, of pages rotated, deleted, duplicated or moved, of images inserted as they are, converted, in HEIC format or with corrected orientation, and of pages rendered at a lower resolution (all as ranges), whether the original was updated in place or a new document was created, and whether the original protection was reapplied, form fields were written into the page and bookmarks were added back.
- PDF compression
- The numbers of inputs and outputs, of images downsized, not downsized and black-and-white, of downsized images whose transparency was also downsized, that stayed lossless or that were converted from CMYK to RGB, and how many times the file was compressed (all as ranges), the kinds of reasons images were not downsized, whether the target size was met and the kind of reason it was not met, the range of how much smaller the file got, whether the original protection was reapplied, and whether the original PDF was returned unchanged.
- PDF cropping and page numbers
- The numbers of inputs and outputs and of pages cropped, numbered or with their margins reduced (all as ranges), how the margins were set, how the pages to crop or number were chosen, the number format and position, the range of the starting number, that the original was updated in place, and whether the original protection was reapplied.