ALAC vs FLAC: Apple Lossless and FLAC Compared

By the M4AtoMP3.org editorial team · October 21, 2026 · 9 min read

If you rip CDs, buy music from lossless stores or download hi-res albums, you will eventually have to pick between FLAC (Free Lossless Audio Codec) and ALAC (Apple Lossless Audio Codec, stored in .m4a files). Both preserve every bit of the original recording. The decision is not about sound quality at all — it is about which devices and software you use, and how much you care about a few percent of disk space.

The short answer

• Mostly Apple devices and the Music app? Use ALAC. It imports, syncs and plays natively everywhere in Apple’s ecosystem.
• Android, Windows, Linux, a network streamer or a dedicated music player? Use FLAC. It is the de facto standard for lossless audio outside Apple.
• A mix of both? Keep a FLAC master library and convert to ALAC (losslessly) for Apple devices, or vice versa. Nothing is lost either way.

What “lossless” means

Lossless compression works like a ZIP file for audio. The encoder finds patterns and redundancy in the waveform and stores them compactly; the decoder rebuilds the original samples exactly. Decode an ALAC or FLAC file and compare it to the CD, and every sample matches. This is completely different from lossy formats like MP3 and AAC, which permanently discard sound judged inaudible. For the full picture see lossy vs lossless audio.

History in one paragraph each

FLAC was released in 2001 by Josh Coalson and is now maintained by the Xiph.Org Foundation. It is open source, royalty-free and formally specified, which is why it spread to almost every operating system, player and streaming device. Many hi-res music stores sell FLAC by default.

ALAC was introduced by Apple in 2004 for iTunes and the iPod. Apple open-sourced the codec under the Apache licence in 2011, so other software can now read and write it freely. ALAC audio is stored in the same MPEG-4 container as AAC, using the .m4a extension — which is why a file’s extension alone does not tell you whether an M4A is lossy or lossless.

Side-by-side comparison

Sound quality

Identical. If someone tells you they hear a difference between ALAC and FLAC copies of the same rip, the cause lies elsewhere: different masters, different volume levels, or a player applying sound check or resampling. Blind tests between lossless formats are a coin toss because there is literally no difference in the decoded data.

File size

FLAC tends to compress a little better. On a typical pop or rock CD rip, FLAC at the default level 5 might land at 55% of the WAV size and ALAC at 57%. Over a 1,000-album library that is a few gigabytes — noticeable on a phone, negligible on a hard drive. FLAC also lets you choose compression levels 0–8; higher levels shrink files slightly at the cost of slower encoding, while decoding speed barely changes.

Device and software support

This is the deciding factor.

Apple: the Music app on Mac, iPhone and iPad imports and syncs ALAC but not FLAC. iOS can play FLAC from the Files app and third-party apps, but your FLACs will not appear in the Music library. If you live in Apple’s world, ALAC is far less hassle.

Android: FLAC is supported natively and by virtually every music app. ALAC is not guaranteed by Android itself: apps such as VLC and Poweramp play it, but some built-in players and many car head units do not.

Windows: Windows 10 and 11 play both, and display FLAC tags in File Explorer. Players such as foobar2000, MusicBee and VLC handle both.

Hi-fi streamers, DAPs and car systems: FLAC is close to universal. ALAC support is common on newer gear but far from guaranteed. Check the manual.

Streaming services: irrelevant for your own library; they stream in their own formats.

Metadata

Both formats store rich tags and embedded cover art. FLAC uses Vorbis comments, which accept any field name, which is handy for classical music (composer, conductor, orchestra). ALAC uses the iTunes tag set, which covers the common fields well and is read by everything that understands M4A. Converting between them usually preserves the standard fields; unusual custom fields may be dropped.

Converting between ALAC and FLAC

Because both are lossless, you can convert back and forth as often as you like with zero quality loss.

With ffmpeg:

ffmpeg -i song.flac -map 0:a -map 0:v? -c:a alac -c:v copy song.m4a
ffmpeg -i song.m4a -map 0:a -map 0:v? -c:a flac -c:v copy song.flac

The -map and -c:v copy options carry the cover art across. GUI tools such as dBpoweramp, foobar2000 and XLD (Mac) do the same with batch support and careful tag mapping. The Music app can also convert imported files to Apple Lossless via File › Convert after setting Import Settings to Apple Lossless.

Converting to MP3 for older devices

Lossless files are big — 25–35 MB for a typical track — and some cars and players do not support either format. Converting a copy to MP3 at 256–320 kbps gives you files about a quarter of the size that sound identical to almost everyone. Keep the lossless originals as your master. Our FLAC to MP3 and M4A to MP3 converters handle both formats in the browser, so files stay on your device.

Hi-res audio

Both formats support 24-bit and high sample rates such as 96 kHz and 192 kHz. Apple Music’s lossless and hi-res lossless streams use ALAC. Most hi-res download stores offer FLAC, and some offer ALAC as an option. Hi-res files are large — a 24/192 album can exceed 2 GB — and whether the extra resolution is audible is debated; for listening, 16/44.1 lossless is already beyond what most ears and rooms can resolve.

Which should you choose?

How to check which format a file really is

Because ALAC uses the .m4a extension, it’s easy to mistake it for AAC. To check:

• Mac Finder: select the file and press Cmd+I; More Info shows the codec (“Apple Lossless” or “AAC”).
• Music app: add the Kind column — it reads “Apple Lossless audio file” or “AAC audio file”.
• Windows: Properties › Details shows the bitrate; anything above about 600 kbps for a stereo track is almost certainly lossless.
• Any platform: ffprobe file.m4a reports alac or aac.

A practical setup for mixed households

A common situation: one person uses an iPhone and a Mac, another an Android phone and a Windows laptop, and there’s a network streamer in the living room. A setup that keeps everyone happy:

1. Keep one master library in FLAC on a computer or NAS, tagged carefully.
2. Point the streamer and Android devices at the FLAC library directly.
3. For Apple devices, convert a copy to ALAC (lossless, so nothing is lost) with XLD, dBpoweramp or ffmpeg, and import that copy into the Music app.
4. For the car or an old MP3 player, make a separate MP3 copy at 192–320 kbps.

Only the master needs backing up; the copies can always be regenerated from it.

Summary

ALAC and FLAC sound exactly the same — both are perfect copies of the source. FLAC is slightly smaller, more widely supported outside Apple and includes an audio checksum; ALAC is the smooth choice inside the Apple ecosystem. You can convert between them losslessly at any time, and make MP3 copies whenever a device needs them.

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