FLAC vs ALAC: Lossless Formats Compared

Both FLAC and ALAC promise the same thing: perfect audio quality in a smaller file than WAV. Both deliver on that promise. The question is which one fits your ecosystem.

What They Are

FLAC (Free Lossless Audio Codec) is an open-source lossless codec maintained by the Xiph.Org Foundation. It is the most widely used lossless format across platforms and devices.

ALAC (Apple Lossless Audio Codec) is Apple's lossless codec, stored in M4A containers. Apple open-sourced the codec in 2011, but it remains primarily an Apple ecosystem format.

Both compress audio without losing any data. Decompress either format and you get the exact original PCM samples, bit for bit.

Compression Ratio

FLAC and ALAC achieve similar compression ratios, typically reducing file size to 50-60% of the original WAV. In practice:

A 40 MB WAV track becomes roughly 22-25 MB in FLAC
The same track becomes roughly 23-26 MB in ALAC

FLAC is slightly more efficient in most tests, saving 1-3% more space. FLAC also offers adjustable compression levels (0-8). Higher levels compress more but encode slower. ALAC has no such adjustment.

Compatibility

This is the deciding factor for most people.

FLAC is supported by:

Android phones and tablets (native)

Windows (native from Windows 10)

Linux (native everywhere)

Most standalone music players and DACs

Streaming services (Tidal, Amazon Music, Qobuz)

Car audio systems (many modern vehicles)

ALAC is supported by:

iPhone, iPad, Mac, Apple TV, HomePod (native)

iTunes and Apple Music

Some Android players (with third-party apps)

Limited support on Windows without additional software

FLAC on Apple devices: Apple added native FLAC playback support in iOS 11 and macOS High Sierra. You can play FLAC files on modern Apple devices. However, the Apple Music app and iTunes do not manage FLAC in their libraries natively. They prefer ALAC.

Metadata and Tagging

Both formats support embedded metadata including album art, track titles, artist names, and more. FLAC uses Vorbis comments, which are flexible and well-standardized. ALAC uses the MP4/M4A tagging system, which is also mature and well-supported.

For practical purposes, both handle metadata equally well. Most tagging software supports both formats.

Streaming and Hi-Res Audio

For lossless streaming, both formats work. Apple Music uses ALAC for its lossless tier. Tidal, Amazon Music HD, and Qobuz use FLAC. If you subscribe to Apple Music Lossless, your downloads are ALAC. Most other services deliver FLAC.

Both formats support hi-res audio up to 24-bit/192 kHz and beyond.

Which Should You Choose?

Choose FLAC when:

You use Android, Windows, or Linux primarily

You want the broadest hardware support

You use non-Apple streaming services

You value open-source software

You want adjustable compression levels

Choose ALAC when:

You live in the Apple ecosystem (iPhone, Mac, HomePod)

You use Apple Music or iTunes to manage your library

You want seamless sync across Apple devices

You share music with other Apple users

Converting Between Them

FLAC to ALAC and ALAC to FLAC conversions are completely lossless. No audio quality is lost because both are lossless formats. The audio data is preserved perfectly. You can convert M4A to FLAC or convert FLAC to M4A whenever you need to switch ecosystems.

The Bottom Line

Pick the format that matches your devices. Apple household? Use ALAC. Everything else? Use FLAC. If you archive music seriously, FLAC is the safer long-term bet because of its broader support and open-source foundation.