Tool 07 · AAC to MP4 · Free · No signup
AAC to MP4.
A .aac file is the raw stream that normally lives inside an M4A or MP4, with no container around it. Drop it, add the cover, export a 1080p MP4 that any player accepts. Converted on your own machine.
01 Audio
Analyzed on your device. Nothing uploads.
02 Style
03 Details
04 Export
Add a track above first.
Made with this tool
How to convert AAC to MP4
A .aac file is an ADTS stream: the same AAC audio an M4A holds, but without the container that gives a player its length, its seek table and its cover. Recorders, radio capture tools and some converters write it, and a fair number of players and every video platform refuse it. This page puts the audio in an MP4 with a picture, on your machine.
- Drop the .aac file on the page: a radio recording, an export from a recorder, a captured stream. Chrome, Edge and Safari decode the raw stream on your device.
- Keep Still for the cover alone, or pick Bars, Halo, Vinyl, Film or Line for a visualizer around it.
- Upload a cover (a raw .aac carries none) or type the title and a typographic cover is made. Choose 16:9 for YouTube, 9:16 for Reels and TikTok, 1:1 for feeds.
- Choose the whole file (up to ten minutes) or a clip and press Export. The MP4 downloads with the audio as AAC.
Related
- MP3 to MP4The same converter for a MP3 file.
- M4A to MP4The same converter for a M4A file.
- WAV to MP4The same converter for a WAV file.
- FLAC to MP4The same converter for a FLAC file.
- OGG to MP4The same converter for a OGG file.
- MP3 to videoThe same converter with the visualizer first.
- Audio to videoEvery format, and the table of what each one does here.
- Music visualizerFor songs: nineteen styles that follow the beat.
- Waveform video makerFor a podcast or a voice note: a waveform that moves with the voice.
- Album cover makerNo cover at all? Make one from the title and artist.
- Audio converterNeed the audio as MP3 or WAV, not a video? Convert it here.
- MP3 tag editorNo cover in the file, or the wrong title? Fix the tags first.
- Audio trimmerOnly need part of the track? Cut it to that part first.
Questions
What is a .aac file, as opposed to an M4A?+
The same kind of audio without a container. An M4A wraps AAC in an MPEG-4 file with a length, a seek table and room for a cover; a .aac is the bare stream. That is why some players cannot seek in it and why platforms refuse it.
Could I just rename .aac to .mp4?+
No. MP4 is a container with its own structure; renaming the stream produces a file that players and uploaders reject. The conversion here builds a real MP4 around the audio and a picture.
Is the audio encoded again?+
Yes. The stream is decoded and encoded again as AAC for the MP4, at a high bitrate. A second pass is not something you will hear on a typical recording; keep the original if you want the untouched stream.
Which browsers decode a raw .aac?+
Chrome and Edge, tested here, and Safari. If a browser refuses the file, Chrome is the safe choice.
Does my file get uploaded?+
No. The file is decoded, drawn and encoded in your browser with the WebCodecs API. Nothing leaves your machine, there is no queue and no watermark.
How long can the file be?+
Up to ten minutes per export, at 1080p, free. A longer file, a full album side or a podcast episode, goes out in parts for now: set the start, export ten minutes, set the next start. Pro, which is coming, renders the whole file in one piece on our servers.
Which frame for YouTube, and which for Reels?+
16:9 for YouTube, the whole file. 9:16 for Reels, Shorts and TikTok, usually a 15, 30 or 60 second clip from the best part. 1:1 for feeds. The frame switch sits beside the player and every style has its own layout for each.