Convert mp4 to aac
Converted on your device. Files never leave this tab. Output tops out around 2 GB.
Nothing is uploaded
The converter runs inside this page. Cut your network after it loads and it still works.
No account, no daily limit
No sign-up, no daily limit, no watermark, no queue behind other people's files. Batch as many MP4 files as you like.
Real AAC output
Encoded by ffmpeg, the same library the command-line tools use — not a renamed extension.
About MP4
MPEG-4 Part 14
An ISO container standard (ISO/IEC 14496-14) based on Apple's QuickTime format. It usually holds H.264 or H.265 video with AAC audio. Use it when a video has to play on any phone, browser, TV or editing app.
About AAC
Advanced Audio Coding
The lossy codec standardized in MPEG-2 and MPEG-4 as a successor to MP3, generally sounding better at the same bitrate. A .aac file is a bare ADTS stream without the MPEG-4 container an M4A has. Use it for players and streaming tools that want a raw AAC stream; for a music library, M4A holds the same audio with better tagging.