Add your ALAC file
Drop one or more .alac files onto the converter above, or browse for them. They load into browser memory only — nothing is uploaded, so there is no size-based pricing and no server queue.
ALAC to AAC
Re-encoding .alac audio as .aac changes how the sound is compressed and which players will accept it. Free, private, and validated — the file never leaves your browser.
Private for supported formats — processed in your browser
Runs on your deviceConvert supported files
Drop ALAC files here
Batch files can each use a different output. Nothing uploads for local conversions.
Working inputs include camera RAW, browser-local audio/video, PDF, CBZ/CBR comics, office documents, ebooks, markup, 3D models, structured text, images, and archives.About converting Apple Lossless audio to AAC audio
Re-encoding .alac audio as .aac changes how the sound is compressed and which players will accept it. ALAC, the Apple Lossless Audio Codec, compresses music with zero quality sacrifice, and the .alac extension is occasionally used to label such files explicitly even though the codec normally travels inside an .m4a container. Decoding reproduces the original samples exactly, making it Apple's counterpart to FLAC.
An .aac file holds raw Advanced Audio Coding data, usually as an ADTS stream. AAC was designed as MP3's successor and delivers audibly better quality at the same bitrate, though the bare .aac extension is rarer than AAC audio traveling inside .m4a or .mp4 files. For this route the practical draw is noticeably more efficient than MP3 at equal bitrates and hardware decoding in essentially every phone and TV — balanced against raw ADTS files handle tags and cover art poorly, which is worth knowing before you commit a large batch.
Why convert ALAC to AAC?
The practical trigger for this conversion is usually a mismatch: with .alac, compresses slightly worse than FLAC on average. Switching to .aac buys you noticeably more efficient than MP3 at equal bitrates, which is why it is the better fit for receiving the audio track copied out of MP4 video without re-encoding. Because the conversion runs locally, trying it costs nothing but a few seconds of compute on your own machine.
ALAC vs AAC at a glance
| Aspect | Apple Lossless audio (.alac) | AAC audio (.aac) |
|---|---|---|
| Format type | Lossless — every pixel or sample is preserved exactly | Lossy — discards detail it judges invisible to shrink files |
| How it stores data | linear-prediction compression conceptually similar to FLAC, typically reaching 40 to 60 percent of PCM size | a pure MDCT transform codec, free of the hybrid filterbank compromise that limited MP3 |
| Strongest at | building a lossless library that syncs cleanly to iPhones and the Music app | receiving the audio track copied out of MP4 video without re-encoding |
| Weak spot | compresses slightly worse than FLAC on average | raw ADTS files handle tags and cover art poorly |
| Metadata | inherits the full iTunes metadata atom set from its MPEG-4 container, including artwork, composer, and grouping fields | no standard tag container exists for raw ADTS streams; ID3 tags are sometimes prepended but poorly supported, so wrapping in .m4a is the reliable way to tag AAC |
Pick AAC as the output
Select .aac in the output menu next to each file. The menu only offers targets this engine can genuinely produce, so if AAC is selectable, the route is real and validated.
Convert on your device
Press Convert. The transcode runs on an FFmpeg engine compiled to WebAssembly, so the audio never leaves your device.
Verify and download
Each result is signature-checked before the download unlocks, so a failed encode can never masquerade as a valid AAC file. Outputs keep the original filename with the .aac extension.
ALAC to AAC questions, answered
Will converting ALAC to AAC lose quality?
Some. Since alac is lossless-oriented and aac is lossy-oriented, the encoder will discard detail it judges least visible; the quality slider controls how aggressive that is. Keep the original .alac if you may need a pristine master later.
Is it private to convert ALAC files here?
Yes — the .alac file is processed inside your browser tab and never uploaded. The transcode runs on an FFmpeg engine compiled to WebAssembly, so the audio never leaves your device. Close the tab and the file is gone from memory.
Where will the AAC file work?
AAC decoding is built into every browser, phone, and operating system, whether the audio arrives as a raw .aac stream or inside an .m4a wrapper. The last holdouts are elderly MP3-only car stereos and bargain portable players.
Will the AAC file be bigger or smaller than my ALAC?
Smaller, usually dramatically so — that is the main reason this route exists. The quality slider trades size against fidelity; the default sits at the point where most people cannot spot the difference.
What happens to the metadata in my ALAC file?
This converter strips container metadata deliberately (the FFmpeg command runs with metadata mapping disabled) so exported files do not leak recording details. In the source, inherits the full iTunes metadata atom set from its MPEG-4 container, including artwork, composer, and grouping fields; none of it is transmitted anywhere because the file never leaves your browser.
Can I convert AAC back to ALAC?
Yes — the reverse route exists as a separate tool. Bear in mind that round-tripping .alac → .aac → .alac is not a perfect undo when any lossy step is involved; keep your original if fidelity matters.