Step 1: Supply your AIFF files using the button above or by haul and lay.
Step 2: Click the 'Convert' button to start the conversion.
Step 3: Get your converted AAC files.
AIFF to AAC Conversion FAQ
What does the AIFF to AAC audio converter do?
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AIFF is lossless audio; AAC is lossy. The converter re-encodes the waveform at a configurable bitrate. The result is much smaller but discards some inaudible frequency content — usually transparent at 192 kbps+.
What bitrate should I pick for AAC?
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320 kbps for archival quality, 256 kbps for transparent listening on most speakers, 192 kbps for streaming, 128 kbps when file size dominates. Below 96 kbps artifacts become audible on percussive content.
Is the AIFF to AAC conversion reversible?
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You can convert the AAC back to AIFF on this site. If either format involved is lossy, the round-trip is not bit-perfect even though it is visually or audibly close.
How much smaller will the AAC be than my AIFF?
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Typically 5-10x smaller for images, 5-15x smaller for audio. Exact ratio depends on the chosen quality level and the content — flat solid-colour images and silent audio compress far more than detailed photos or busy soundtracks.
How much quality do I lose converting AIFF to AAC?
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Some, and it is permanent — this is the one direction where information is genuinely thrown away. AIFF holds every sample exactly; AAC discards what a psychoacoustic model predicts you will not hear. At 192 kbps and above that prediction is good enough to be transparent on most material and most equipment. Keep the AIFF as your master, because you cannot get back to it from the AAC. AIFF stores uncompressed big-endian PCM — the Apple-side equivalent of WAV, with the same bit-for-bit fidelity. AAC is lossy but more efficient than MP3, and it handles up to 48 channels natively rather than being bolted onto a stereo design.
What exactly is an AAC file?
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A bare run of encoded audio frames with no container wrapped around them. That is why two AAC files can usually be joined by simply putting one after the other, and equally why everything beyond the audio itself — a length, a seek index, cover art — has to be bolted on as a convention rather than being part of the format, so a player often has to read the whole file to work out how long it is. It is about the simplest thing that can be called an audio file, which is exactly why it turns up inside other containers more often than on its own.
Is AIFF on its way out?
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It is being quietly succeeded rather than switched off. Everything that plays it today will keep playing it — formats do not stop working — but new encoders and new hardware increasingly default to its replacement, so the real question is whether these files have to open on something bought ten years from now. For anything shared or published, converting is cheap insurance. For a personal library that already plays fine, leaving it alone is a defensible answer. AIFF is as large as WAV with worse support outside the Apple world, so it is a poor choice for distribution.
Is AIFF free to use and distribute?
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Yes, without conditions worth worrying about. The specification is public, anyone can implement an encoder or decoder without asking or paying, and nobody can change those terms later — which is why it turns up in open-source tooling, in game engines and anywhere a licence negotiation would have killed the project. Converting away from it does not undo that; the files you already have stay exactly as usable as they were.
Who defines AAC?
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A standards body rather than a company, which is most of the reason it is everywhere. AAC was specified through the international process that produces the MPEG standards, so broadcasters, phone manufacturers, browser vendors and streaming services all implemented the same document instead of licensing somebody's product. The practical consequence is boring and useful: an AAC made by one tool decodes identically in another, and there is no vendor whose support could be withdrawn. AAC is Advanced Audio Coding, standardised in 1997 as MPEG-2 Part 7 and designed explicitly to replace MP3.
Is there a file-size limit when converting AIFF to AAC?
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Anonymous uploads are capped at a generous default; signed-in free accounts get a higher cap, and Pro accounts have no per-file limit. Browser memory is usually the practical constraint long before our server-side limits kick in.
Can I batch-convert several AIFF files to AAC at once?
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Yes. Drop or pick multiple AIFF files in one upload — the converter processes them in parallel and returns a ZIP of the AAC results. There is no need to repeat the upload step per file.
What happens to my AIFF files after the conversion?
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Uploaded files and AAC outputs are auto-deleted after a short retention window. We do not inspect, share, or train on user files. Direct download links are time-limited and tied to your session.
