What happens when you convert AAC to AIFF
- The audio is decoded and written as 16-bit big-endian PCM.
- AIFF is lossless, but it cannot restore what the AAC encoder already discarded. The AIFF will sound identical to the AAC and be several times larger.
How to convert AAC to AIFF online
- Press "Choose AAC files" and select one or more files, or drag them onto the box. You can add files of any size your device can hold in memory.
- Adjust the settings if you need to: the bitrate controls quality and size. The defaults suit most people.
- Press "Convert to AIFF". The first audio or video conversion downloads the converter engine, about 32 MB, which your browser then keeps for next time.
- Save each AIFF with its download button. Close the tab and every trace of the files is gone from memory.
Why convert AAC to AIFF?
AAC files usually come from iTunes and Apple Music, YouTube audio and streaming. People convert them to AIFF because AIFF is the uncompressed format Logic Pro, GarageBand and many Mac tools prefer.
In short, AAC is good at what it was made for, and AIFF is the more practical choice when the file has to play on another device or app. AAC plays in all current browsers and on Apple and Android devices, while AIFF plays in Safari; Chrome and Firefox do not play it.
How to convert AAC to AIFF on Windows, Mac, iPhone and Android
On Windows
Open this page in Chrome, Edge or Firefox, drag your AAC files in from File Explorer, and press Convert. Each AIFF is saved to your Downloads folder. If you prefer a desktop program, VLC can also convert AAC to AIFF: choose Media, then Convert / Save.
On a Mac
Safari, Chrome and Firefox all work. Drag the AAC files from Finder onto the drop zone and the AIFF files land in Downloads.
On iPhone and iPad
Open the page in Safari and tap Choose AAC files. You can pick from Photos or from the Files app. The converted AIFF appears in Files, in the Downloads folder.
On Android
Open the page in Chrome, tap Choose AAC files and pick them from Files or your gallery. The AIFF is saved to the Download folder, where any file manager can find it. Keep the screen on while a long video converts, because Android may pause a tab in the background.
Best settings for AAC to AIFF
AIFF is lossless, so there is no quality setting: every sample of the decoded AAC is kept. What changes is size. CD-quality stereo, 44.1 kHz at 16 bits, takes about 10 MB per minute as uncompressed PCM.
Since the AAC was lossy, the AIFF will sound identical to it, not better. Convert to AIFF when a program requires it, not to improve quality.
AAC vs AIFF: the differences
| AAC | AIFF | |
|---|---|---|
| Full name | Advanced Audio Coding | Audio Interchange File Format |
| Type | audio | audio |
| Created by | the Moving Picture Experts Group | Apple |
| First released | 1997 | 1988 |
| Compression | Lossy | Lossless |
| Usually contains | AAC audio in a raw ADTS stream | uncompressed PCM, big-endian |
| In a browser | plays in all current browsers and on Apple and Android devices | plays in Safari; Chrome and Firefox do not play it |
| Common uses | iTunes and Apple Music, YouTube audio and streaming | Logic Pro, GarageBand and Mac audio production |
| MIME type | audio/aac | audio/aiff |
About AAC and AIFF files
What is an AAC file?
AAC was designed as the successor to MP3 and sounds better at the same bitrate, especially below 128 kbps. A bare .aac file is a raw stream with no chapters or cover art; the same audio in a container is usually called M4A.
What is an AIFF file?
AIFF is Apple's uncompressed counterpart to WAV, holding the same audio with bytes stored in the opposite order. Unlike WAV it has a standard place for track names and artwork.
AAC to AIFF not working? Common problems
- The conversion is slow. Audio and container changes take seconds, but re-encoding video runs on your own processor. Lower the resolution to 720p, close other tabs, and keep the device plugged in.
- The tab stops or reloads on a very large file. Browsers limit how much memory one tab can use, around 2 GB and less on phones. Split long recordings or convert them on a computer.
- Song titles are missing. Tags such as title and artist are copied when AIFF can store them, but cover art is not carried over.
Convert AAC to AIFF with ffmpeg
This converter runs ffmpeg inside your browser. If you would rather use the ffmpeg command line on your own computer, this command produces an equivalent AIFF with the same kind of settings:
ffmpeg -i input.aac -vn -c:a pcm_s16be output.aiffReplace input.aac with the name of your file. For a whole folder of AAC files, run the command in a loop, or drop them all on the converter above, which processes them one after another.
AAC to AIFF converter FAQ
Will I lose quality converting AAC to AIFF?
No further quality is lost, because AIFF is written losslessly. Detail the AAC compression already removed does not come back.
Why is the AIFF a different size from the AAC?
The AIFF is usually larger, because it stores every sample without compression losses, while the AAC was compressed lossily.
Are my AAC files uploaded anywhere?
No. The conversion runs inside this browser tab using ffmpeg compiled to WebAssembly, so your files stay on your device. You can disconnect from the internet after the page and converter engine have loaded and it still works.
Can I convert several AAC files to AIFF at once?
Yes. Select or drop as many files as you like; they are converted one after another and each gets its own download button.
How do I open an AIFF file?
AIFF plays in Safari; Chrome and Firefox do not play it. AIFF is common for Logic Pro, GarageBand and Mac audio production.
Is this AAC to AIFF converter free?
Yes. There is no sign-up, no watermark and no limit on how many files you convert. The site is paid for by advertising, and because conversions run on your device there is no server cost per file.
Can I convert AAC to AIFF on my phone?
Yes. The converter works in Safari on iPhone and iPad and in Chrome on Android. Converted files are saved to the Downloads folder.