Turn AIFF files into AAC in a couple of clicks. AIFF is Apple's uncompressed audio counterpart to WAV; AAC is the successor to MP3 — better quality per bit. Some detail is discarded to fit the target format; how much depends on the format and your settings.
Drop your files here
AIFF files (.aiff, .aif, .aifc) · up to 300 MB each
or paste files from your clipboard
Ready when you are
Drop a AIFF file above and FileTools360 will turn it into AAC — right here on your device, without uploading anything.
Drag them onto the drop area, choose them from your device, or paste them from your clipboard. You can queue several at once. Nothing is sent anywhere — the file stays on this device.
The defaults suit most people. Open Advanced to control bitrate, sample rate and channels.
Press Convert. Everything happens on your own device — nothing is uploaded. Download files one by one, or grab them all as a ZIP.
Privacy, in plain words
What “uploaded” normally means. On most online converters, pressing the button copies your file across the internet onto a computer owned by that website. That copy is what the word “upload” means, and it is the part nobody explains.
What happens instead. This site does not do it. There is no server here that receives files, so your AIFF file is read, converted and handed back by the browser you are using right now. It never travels — so there is no copy to store, read, leak or hand over.
Check it yourself in ten seconds
Turn off your Wi-Fi after this page has loaded, then convert a file anyway. It still works, because everything needed is already on your device.
The longer explanation of how this works, and the full detail of what is and is not stored on the privacy page.
An audio file is a conversation. Transcribed by machine — which is cheap now — it becomes searchable text about whoever was speaking. It matters more than it sounds, because of what audio files usually are:
Interviews
a source's voice is identifying even when the name is not said
Voice notes and dictation
thinking out loud, never meant for an audience
Therapy and consultation recordings
clinical material with strict handling rules
Meeting audio
internal discussion, named people, unannounced decisions
A file that is never sent cannot be kept, leaked, subpoenaed or used to train anything. That is a property of how this works, not a promise about how carefully it is run.
AIFF is Apple's uncompressed audio format, functionally equivalent to WAV but with better metadata support and big-endian byte order.
AAC is the successor to MP3 and is the default audio codec for MP4 video, Apple Music and YouTube. At the same bitrate it generally sounds noticeably better than MP3.
The two formats solve different problems, which is why converting between them involves trade-offs rather than a straight upgrade.
| Property | Source | Target |
|---|---|---|
| Compression | Uncompressed | Lossy |
| Introduced | 1988 | 1997 |
| Browser support | Strong on Apple, decent elsewhere. | Excellent across modern devices. |
People make this switch when they run into the limits of AIFF: distribution, or interchange with Windows tools where WAV is safer. AAC is the better fit when modern streaming, or the audio track of a video.
There is also a size argument: AIFF stores data with little or no compression, so the AAC version is normally dramatically smaller for the same content.
AIFF stores your data exactly; AAC does not. Some detail is discarded permanently in exchange for a much smaller file, which is usually the right trade for sharing and publishing. Keep your AIFF original if it is the only copy — the conversion cannot be undone.
On every sample measured, the AAC came out smaller — 3.6× smaller at worst and 5× smaller at best.
| Sample | AIFF in | AAC out | Change |
|---|---|---|---|
| An easy clipThe compressible end of the range — a clean tone, or a moving test pattern — where a codec does its best work. | 172 KB | 32.8 KB | −81% |
| A hard clipThe other end — pink noise, or dense video grain. Close to incompressible by design, and the worst case for every codec. | 172 KB | 47.7 KB | −72% |
Produced by this site's own converter. The same code that runs in your browser, at the same default settings, so these are the bytes you would download.
Samples are generated from a fixed seed rather than taken from real photographs or documents, so the corpus is reproducible and carries no licensing question — and so the numbers predict the shape of your result rather than its exact size. Measured 2026-10-01. The method, and the command that regenerates every figure on this page, are on the how it works page.
Source
Apple's uncompressed audio counterpart to WAV.
Target
The successor to MP3 — better quality per bit.
Going from a lossless source to a compressed format discards audio data permanently. Keep your original if it is the only copy.
Good to know
Runs entirely in your browser
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