ALAC vs FLAC for Apple Users: Why iTunes Treats Them Differently

Two Lossless Formats That Don't Talk to Each Other

ALAC (Apple Lossless Audio Codec) and FLAC (Free Lossless Audio Codec) both compress audio without quality loss. File sizes are within 5% of each other for the same source. Both decode to identical PCM audio.

Apple's tools play ALAC. Apple's tools refuse FLAC. macOS Finder shows FLAC files but can't preview them in QuickLook. iTunes (and Apple Music app, its replacement) imports ALAC and rejects FLAC. iPhones play ALAC and not FLAC.

This isn't a technical limitation. It's a deliberate Apple choice. ALAC was created in 2004 specifically because Apple didn't want to license FLAC. The two formats coexist for the same reason Beta and VHS coexisted: corporate strategy, not engineering.

For Apple-centric music libraries, ALAC is the practical choice. For everywhere else, FLAC dominates. This post covers the conversion workflows, the metadata interactions, and the platform interactions in 2026.

For broader audio format choices, see Audacity Export Settings and Audio Format for Streaming Services.

File Size Comparison

For a 4-minute song from 24-bit 96 kHz source:

ALAC is consistently 2-5% larger than FLAC at the same source quality. Both are roughly 60% the size of WAV.

The compression difference is small enough that storage cost shouldn't decide your choice. Compatibility decides it.

Apple Music App Behavior

If your library lives in Apple Music app: ALAC. Period. FLAC requires a workaround like importing through VLC or third-party players, and even then doesn't sync to iPhone.

Other Player Behavior

For non-Apple ecosystems, FLAC is more universally supported. Apple Watch, HomePod, AirPods Max optimize specifically for ALAC.

Conversion FLAC to ALAC

For Apple Music import:

ffmpeg -i input.flac -c:a alac output.m4a

Note the .m4a extension. ALAC files use .m4a (the same as AAC files do); the audio codec inside is what differs.

For batch conversion of a folder:

for f in *.flac; do
  ffmpeg -i "$f" -c:a alac "${f%.flac}.m4a"
done

Quality is bit-perfect. ALAC and FLAC both decode to the same PCM data.

For programmatic batch work, see Batch Processing Files Guide.

Or use our audio converter for single-file or small-batch work.

Conversion ALAC to FLAC

For non-Apple library import:

ffmpeg -i input.m4a -c:a flac output.flac

Bit-perfect, no quality loss. The file is slightly smaller after conversion (FLAC's compression is marginally more efficient).

Metadata and Tagging

Both ALAC and FLAC support extensive metadata. The tag formats differ:

• FLAC: Vorbis Comments (key-value pairs)
• ALAC: iTunes-style tags inside MP4 atoms

Tools like Mp3tag and Tag Editor handle both formats and translate tags between them.

For album art:

• FLAC: stored as a "PICTURE" block, multiple types supported
• ALAC: stored in the MP4 metadata, single image typically

When converting, art usually transfers correctly but verify in your destination player.

Apple-Specific ALAC Features

Hi-Res Lossless tier:

Apple Music's "Hi-Res Lossless" tier streams up to 192 kHz / 24-bit ALAC. To deliver tracks compatible with this tier:

• Source: 192 kHz / 24-bit master
• Encode: ALAC at 192/24
• Tag with acoustid_id, isrc, and accurate metadata
• Submit through your distributor with "Hi-Res Lossless" toggle

Most consumer ears can't distinguish 96/24 from 192/24, but the tier exists for collectors and audiophiles.

Spatial Audio with Atmos:

When delivering Dolby Atmos for Apple Music, the master is ADM BWF, not ALAC. The stereo deliverable that ships alongside Atmos is ALAC. See Dolby Atmos for Music.

Apple Digital Masters (formerly Mastered for iTunes):

A certification program for masters delivered specifically to optimize Apple Music's lossy delivery. The master is ALAC; Apple's pipeline transcodes to AAC efficiently when the master is ADM-compliant. The label "Apple Digital Masters" appears on certified releases.

When FLAC Is Still Right

Even for Apple-using listeners, FLAC has cases:

Backups and archives: FLAC's wider tool support makes archives more future-proof. ALAC tools could theoretically be deprecated by Apple (unlikely soon, but possible). FLAC has dozens of independent decoders.

Mixed-platform households: if your music library spans Apple Music app on iPhone and Plex/Roon on the network, FLAC is the lower-friction choice. Apple users access via Plex/Roon clients that handle FLAC; non-Apple users get native support.

Exchange with non-Apple users: sharing music via Bandcamp, archive.org, or direct download. FLAC is the de facto standard for downloads outside Apple Music.

Conversion Loss Concerns

There's no quality loss in either direction:

• WAV → FLAC: lossless
• WAV → ALAC: lossless
• FLAC → ALAC: lossless (decoded then re-encoded losslessly)
• ALAC → FLAC: lossless

You can convert back and forth indefinitely without degradation. The two formats are mathematically equivalent representations of the same PCM data.

Storage Math for a Library

For a 1000-album collection:

For Apple Music app, 360 GB is on the edge of "fits on a SSD." For network storage (Plex, Roon), the size doesn't matter much.

Common Issues

Imported ALAC plays as AAC quality in Music app: Music app sometimes treats new imports as compressed. Right-click track > Get Info > Files tab should show "Apple Lossless" codec. If shows AAC, re-import.

FLAC won't import to Apple Music: this is expected behavior. Convert to ALAC first.

Album art missing after conversion: tagger embeds art differently. Use Mp3tag (Windows) or Tag Editor (Mac) to verify art transfer.

iPhone shows ALAC files as smaller bitrate: Apple Music's display shows the streaming-equivalent bitrate, not the source ALAC bitrate. This is cosmetic; the file plays at full ALAC quality.

Hi-Res Lossless not showing as Hi-Res in tier: source must be 88.2 kHz or higher and properly tagged. 44.1/16 source plays as Lossless tier, not Hi-Res.

For broader format conversion paths, see Audio Bitrate Quality Guide.

Frequently Asked Questions

Is one format "better" than the other?

For audio quality: identical. Both are lossless. The choice is platform-dependent: Apple favors ALAC, everywhere else favors FLAC.

Will Apple ever support FLAC?

No announced plans, and after 20 years of ALAC the calculus probably won't change. The third-party tools (VLC, Plex, Roon) handle FLAC on Apple platforms reasonably.

Can I store one library and serve both formats?

With Roon or Plex: yes. Roon stores in any format, transcodes on-the-fly to whatever the playback target needs. Plex similar but with manual transcoding setup.

What about the older AIFF format?

AIFF is uncompressed (like WAV). For lossless compressed: ALAC or FLAC. AIFF has no advantages over WAV for modern use.

Should I rip CDs to ALAC or FLAC?

For Apple-only users: ALAC. For others or hybrid setups: FLAC, with conversion to ALAC as needed for Apple devices.

What about Spotify and Tidal lossless?

Spotify HiFi (in late 2026 finally launching) and Tidal are streaming services; you don't manage their files. Both use FLAC under the hood for streaming, but transparent to users.

Related Reading

• Audacity Export Settings
• ALAC vs FLAC Comparison
• Audio Format for Streaming Services

Bottom Line

For Apple-centric users: ALAC. For non-Apple or hybrid users: FLAC. Both are lossless and within 5% file size. Apple Music app rejects FLAC; FLAC is universally supported elsewhere. Convert with FFmpeg (-c:a alac or -c:a flac); both are bit-perfect. Our audio converter handles single-file conversions.