CAF to FLAC Converter

CAF to FLAC Converter

A .caf file is Apple's Core Audio Format: a container built for Core Audio on macOS and iOS that can wrap almost any payload — uncompressed PCM, Apple Lossless, IMA ADPCM, even AAC. FLAC is the opposite kind of thing: one specific, openly specified lossless codec that decodes bit-for-bit back to the PCM it was given. Converting CAF to FLAC is what you do when a recording needs to survive intact but also needs to open on hardware and software that has never heard of Core Audio. This page covers both formats' specifications, what the conversion actually preserves, and how to drive the options.

CAF Format at a Glance

FLAC Format at a Glance

What the FLAC Inherits From Your CAF

FLAC is always lossless relative to what it is handed. Because CAF is only a wrapper, the honest answer to "will this be lossless?" depends on what was inside the wrapper in the first place.

How to Convert CAF to FLAC

1. Upload Your CAF File: Drag and drop the .caf onto the page or click "+ Add Files" to browse. Several files can be queued and converted with the same settings in one pass.
2. Set the Compression Level: Open the options and move the Compression level slider, which runs from 1 to 12 and starts at 12. Higher values search harder for redundancy, so the file gets smaller and the encode takes longer — the decoded audio is identical at every level.
3. Leave Audio Sample Rate and Audio Channel on "Original" (Optional): Both default to mirroring the source, which is what keeps the copy lossless. Changing them resamples or downmixes, which is a real, irreversible edit. Trim is there if you only need one region of a long capture.
4. Convert and Download: Click "Convert" and save the FLAC. No sign-up, no watermark.

Frequently Asked Questions

Is the FLAC format an actual standard, and is it still maintained?

Yes. FLAC shipped as free software in 2001 and has been hosted by the Xiph.Org Foundation for most of its life, but it only became a formal specification recently: the IETF published RFC 9639, "Free Lossless Audio Codec", on the Internet Standards Track in December 2024. That document is now the normative description of the bitstream, which matters if you are archiving material and want a format whose decoder can be re-implemented from a published spec decades from now.

Will I lose any audio quality converting CAF to FLAC?

Not in the encode itself. FLAC's defining property is that decompression "returns exactly the original data", so the PCM that comes out of a FLAC decoder is byte-for-byte what went in. We verified this on the encoder this converter uses by round-tripping a 24-bit/96 kHz PCM file to FLAC and back: the decoded stream hashed identically to the source. The only caveat is upstream — FLAC cannot restore detail that a lossy codec discarded before the file ever reached us.

Does FLAC preserve high-resolution 24-bit or 96 kHz audio from a CAF master?

Yes. RFC 9639 allows 4 to 32 bits per sample and sample rates from 1 Hz to 1,048,575 Hz, which comfortably covers every high-resolution CAF a DAW is likely to produce, and the encoder records the source bit depth rather than truncating to 16-bit. Leave Audio Sample Rate on "Original" — picking a fixed rate resamples the audio, and that step is not reversible.

How much smaller will the FLAC file be than the CAF?

That depends entirely on the material, because lossless compression can only remove genuine redundancy. Dense, loud, noisy mixes compress the least; sparse, quiet or mono recordings compress the most. As a reference point, uncompressed 16-bit/44.1 kHz stereo PCM runs about 10 MB per minute, and FLAC will typically take a meaningful bite out of that without touching a single sample — but there is no fixed ratio to promise, and any tool that quotes you an exact percentage in advance is guessing.

Which compression level should I pick?

Any of them, as far as audio quality goes — every level decodes to the same samples, so the slider only trades encoding time for file size. The slider starts at 12, the most thorough setting. Drop it if you are converting a very long recording and want the job done sooner; the size penalty for a lower level is usually small compared with the time saved.

My CAF holds AAC audio — is the FLAC still "lossless"?

Technically yes, practically no. FLAC will losslessly preserve the decoded waveform of that AAC, but the AAC encoder already threw information away permanently and no later step recovers it. You also end up with a larger file than the AAC you started with, because you are now storing a lossy waveform with lossless overhead. If the payload is already lossy and size matters, CAF to MP3 or a modern lossy target is the more sensible destination; use FLAC when the source is PCM or ALAC.

Can FLAC carry the markers and annotations that were in my CAF?

Not the Apple-specific ones. CAF can store markers, regions, edit comments, MIDI data, channel layout, peak and overview chunks and a UMID identifier; FLAC's metadata system covers tags, cover art, seek tables and cue sheets, which is a different set. Ordinary tags survive where they exist, but if your workflow depends on embedded markers, keep the CAF as the master and treat the FLAC as the archive or distribution copy.

What actually opens a FLAC file?

Very nearly everything modern. In browsers, FLAC playback via the HTML audio element sits at roughly 96% global support — Chrome 56+, Firefox 51+, Edge 16+, Opera 42+, Safari 13+ with partial support back to Safari 11, and iOS Safari from version 11. Off the web, VLC, foobar2000, Audacity, most Android devices and modern macOS and Windows builds all handle it. Internet Explorer never did, and Opera Mini still does not.

How are my uploaded files handled?

Your CAF is uploaded over an encrypted connection, converted on our servers, and deleted automatically a few hours later. There is no sign-up, no watermark, and files are never shared or made public. If you need an uncompressed file for a desktop editor rather than a compressed-but-lossless one, CAF to WAV writes plain PCM instead.