AAC Converter
FileFlip converts AAC files into 12 other formats entirely inside your browser, using WebCodecs and FFmpeg compiled to WebAssembly. The AAC file is never uploaded to a server: it is read off your disk, converted on your own machine, and saved back by the browser. There is no file-size limit and no account to create.
How do I convert an AAC file?#
- Drop your AAC file onto the converter at the top of this page, or click it to pick one from your computer.
- Choose the format you want out of it. FileFlip downloads the engine that conversion needs, once, and your browser caches it.
- Conversion starts the moment you pick the format, and the result is yours to download. The work happens in this tab, so nothing is uploaded and nothing is queued.
Is it safe to convert AAC files online?#
Yes, because nothing is uploaded. FileFlip converts AAC files inside the browser tab you already have open, using WebAssembly builds of the same engines a desktop converter would install. Your file is read from your own disk into the page's memory, and no request carrying it is ever made.
You do not have to take that on trust. Open your browser's network panel, run a conversion, and you will see the engine come down and your file go nowhere. There is no upload, no server-side copy, no retention window, and no account tied to what you converted.
How FileFlip works lists every engine, its version and its download size, and shows how to check for yourself that nothing leaves your machine.
What happens to a AAC file#
FileFlip converts AAC into 12 formats with WebCodecs and FFmpeg, all of it inside the browser tab. Each conversion below names the engine it uses, what it downloads, and exactly what that conversion keeps or drops.
| Category | Audio Files |
|---|---|
| File extension | .aac |
| FileFlip support | Read only, so it is a source rather than a target |
| Conversions available | 12 |
| Engines | WebCodecs and FFmpeg |
| Downloaded to your browser | 30.8 MB on the first conversion, then cached |
What is an AAC file?#
An AAC file, in this raw form, holds an ADTS bitstream of audio compressed with Advanced Audio Coding, the codec MPEG standardized in 1997 as a successor to MP3 that delivers better quality at the same bit rate.
Use raw AAC when a pipeline needs the bitstream itself, such as for streaming or broadcast, and per-file metadata isn't required.
Convert AAC to MP3 when a destination app or device doesn't support AAC playback, keeping in mind the conversion cannot add back what the original AAC encoding discarded.
The AAC file format reference covers the specification, the programs that open one, and what each conversion keeps or drops.
AAC questions people ask#
What's the difference between AAC and MP3?
AAC is a newer, more efficient lossy codec than MP3. Standardized in 1997 versus MP3's 1993, it uses better psychoacoustic modeling to sound cleaner than MP3 at the same bit rate, especially below 128 kbps. Both throw away audio data permanently, so neither is a lossless upgrade over the other.
Is a .aac file the same as an M4A file?
No. Both usually hold AAC-compressed audio, but a .aac file is a raw ADTS bitstream with no container around it, while .m4a is that same AAC audio wrapped in an MP4 container that adds proper metadata support, seeking and chapter markers. Most consumer software expects the M4A version.
Does converting AAC to MP3 lose quality?
Yes, converting AAC to MP3 loses quality, because both are lossy codecs and the conversion has to decode the AAC and re-encode it in MP3's different, also lossy, format. The result carries artifacts from two compression passes instead of one, an effect known as generation loss.
What plays AAC files?
Apple's Music and QuickTime Player, VLC, and every modern browser and mobile OS play AAC audio, since it's the default codec for iTunes, YouTube and most streaming services. A raw .aac file specifically is less universally recognized than the same audio in an M4A container, so some players need it renamed or re-wrapped first.
Why does my AAC file have no song title or album art?
A raw .aac file is just the ADTS audio bitstream with no defined place to store tags, so players can't show a title, artist or album art the way they can for an MP3 or M4A. Converting the audio into an M4A or MP3 container adds the missing space for that metadata.