MP4 to MP3
Drop an MP4 in and take the sound out as an MP3 — no upload, no account, no size cap. The conversion runs inside this tab, which is why it still works with your Wi-Fi switched off.
MP4 to MP3, in this tab
Your video is read off your own disk. Nothing is sent anywhere.
Starting the extractor…
What actually happens to the audio
An MP4 is a container. Inside it there are separate streams — one carrying the picture, one carrying the sound — and the sound is almost always AAC. MP3 is a different codec, so converting means decoding that AAC back to raw audio and compressing it again with a different encoder. That second pass costs a little quality. At 192 kbps and above, on one pass, almost nobody can hear it.
If that bothers you, there is a way around it that is not a setting: take the audio out as M4A instead. An .m4a is the same container the MP4 already uses, holding the same AAC stream, so the audio is lifted out untouched — every sample identical, and it finishes in seconds no matter how long the film is. Choose MP3 when something on the other end demands MP3; choose M4A when you just want the sound.
Which bitrate to pick
The bitrate is how many kilobits each second of audio is allowed to use. More is not better past a point, and it can never be better than the soundtrack you started with: asking for 320 kbps from a video whose audio is 128 kbps AAC gives you a file two and a half times the size containing the same audio, slightly degraded by the re-encode. The panel above reads the real bitrate out of your file and says so when that is what you are about to do.
| Bitrate | One hour of audio | Right for |
|---|---|---|
| 64 kbps | about 28 MB | A lecture, an interview, a podcast — speech only |
| 128 kbps | about 56 MB | Background music, anything going on a phone |
| 192 kbps | about 84 MB | The default. Music you will actually listen to |
| 320 kbps | about 140 MB | The ceiling MP3 allows. Rarely worth it from a video |
Big videos, and why this one copes
Most browser converters read the whole video into the tab's memory, which is why they fall over on a two-hour recording. This one mounts the file instead: FFmpeg is handed the file itself and reads the slices it needs as it walks through, so it skips the picture entirely and only the soundtrack passes through memory. A 3 GB screen recording of a webinar is a 40 MB MP3 and the difference never has to be held anywhere.
The limit that remains is around 2 GB, where the WebAssembly build's file addressing gives out, and it is lower on an iPhone because Safari gives a tab less room. That is the one case where the app is the better tool: it reads the file directly with no browser in between.
One thing this will not do
It does not take links. There is no box to paste a YouTube, TikTok or Instagram URL into, and there will not be one — this works on videos that are already on your device: something you recorded, something someone sent you, an export from an editor.
Step by step
Choose the MP4
Drag it onto the box or click to pick it. Large files are fine: the video is read in slices rather than loaded into memory, so the picture never has to fit anywhere.
Pick a bitrate
192 kbps is the default and is transparent for most listeners. 64 or 96 is plenty for a lecture or an interview and makes a much smaller file.
Convert and download
The MP3 appears with a player so you can check it before saving. The name comes from the video, with the new extension.
About converting MP4 to MP3
Does MP4 to MP3 lose quality?
Yes, a little, and no converter can avoid it — the soundtrack in an MP4 is AAC, so making an MP3 means encoding it a second time. At 192 kbps and above the difference is inaudible to almost everyone on a single pass. Extracting to M4A instead avoids it completely, because that is a copy rather than a conversion.
Learn more: Keeping the originalIs there a file size limit?
None that we impose. The browser tab's own ceiling is about 2 GB, and you will hit it long before you hit anything we set, because the video is never loaded into memory — only the soundtrack is read.
Learn more: How it worksHow long does it take?
An MP3 encode runs at roughly twenty times real time in the tab, so a 10-minute video is about half a minute and a 90-minute film is a few minutes. Extracting to M4A instead is seconds, because nothing is re-encoded.
Learn more: MP4 to M4ACan I convert several MP4s at once?
Yes. Add more files and each one is converted in turn with its own download. The iPhone app does one video at a time, so a folder of them is a job for this page.
Learn more: Video to MP3Why does my MP3 sound quiet compared with the video?
Extraction changes the format, not the level, so the audio is exactly as loud as it was in the video. Players that apply their own normalisation can make the same file sound different in two apps.
Learn more: Extract audioGet it on your phone
Your videos are usually on the phone already, and moving one to a laptop to get the sound out is the slowest part of the job. The app converts them where they are — offline, with no browser involved.
- Converts straight from the camera roll or Files
- MP3, M4A, AAC and WAV at 64–320 kbps
- Works with no signal — nothing is uploaded there either
- Twelve audio tools: cutter, fade, speed, pitch, equalizer, denoise and more
Free to install with one free conversion, then a subscription for unlimited use. One video at a time — the queue on this website is the place for a folder of them. 4.6 out of 5 from 41 ratings on the App Store, read on 19 September 2026.