Convert MP4 to AAC
Choose your MP4 file and get a AAC file in seconds. Nothing leaves your device.
Converter
- FilesOne or many, images and videos mixed
- FolderEvery matching file inside, subfolders included
- ArchiveZIP, RAR, 7z or TAR: convert the contents or the archive itself
Drop files, folders or archives here
Unsupported files are skipped. Nothing is uploaded.
Everything runs in your browser. Files are not uploaded.
About this conversion
The sound track is taken out of the MP4 video, handy for music, podcasts, lectures and interviews.
Good to know
Only the sound is kept and the picture is dropped. With several audio tracks, the first one is used.
Raw AAC files carry no tags and seek poorly; M4A is the better choice for music libraries.
How it works
The audio is converted by ffmpeg compiled to WebAssembly. It loads only when you choose a file and runs in a background thread.
Your browser can
- Built-in image codecs
- Hardware video (WebCodecs)
- Multiple threads
- Create AVIF natively
If something is missing, the conversion takes a little longer but still works.
About MP4 (MPEG-4 Part 14)
MP4 is the most compatible video format, usually with H.264 video and AAC audio.
- Sharing videos
- Web video
- Phone and camera recordings
About AAC (Advanced Audio Coding, raw ADTS stream)
A .aac file is a raw AAC audio stream without a container, the codec behind M4A, YouTube and most streaming services.
- Efficient codec with good quality at low bitrates
- Widely supported by hardware decoders
- Simple stream, easy to cut
Related conversions
Frequently asked questions
Are my files uploaded to a server?
No. The conversion runs entirely in your browser with local code. Your files never leave your device, and there is no upload.
Is there a file size limit?
There is no limit on our side, but your browser memory is. Images work for very large files; for videos, files above a few hundred megabytes can fail on devices with little memory.
Will the quality suffer?
That depends on the target format and settings. Use the quality option to balance size and detail; lossless targets keep everything the source contained.
Which browsers are supported?
Current versions of Chrome, Edge, Firefox and Safari. Fast hardware paths are used where available, with a compatible fallback otherwise.