Audio

FLAC vs ALAC vs WAV vs AIFF: Lossless Audio Compared

Published Mar 19, 2026 7 min read By ChangeThisFile Team

Quick Answer

All four formats preserve audio bit-for-bit, but they differ in everything else. FLAC: best compression, widest non-Apple support, open-source. ALAC: Apple's lossless, native Apple device support, open-sourced in 2011. WAV: uncompressed, universal, minimal metadata, 4 GB limit. AIFF: Apple's uncompressed format, better metadata than WAV, same quality and size.

If you care about audio quality, lossless is the floor — not the ceiling. Every format in this comparison preserves the original audio perfectly. Decode any of them and you get the exact same PCM data, sample for sample, bit for bit. The differences between FLAC, ALAC, WAV, and AIFF are about everything except audio quality: file size, metadata support, platform compatibility, and streaming availability.

This isn't a subjective comparison. There's no "FLAC sounds warmer than WAV" — that's audiophile mythology. Lossless means lossless. The decoded output is mathematically identical. The choice between these formats is purely practical: which platforms do you need, how much storage do you have, and how important is metadata?

The Complete Comparison Table

Feature	FLAC	ALAC	WAV	AIFF
Compression	Lossless (50-70% of WAV)	Lossless (50-70% of WAV)	None	None
Audio quality	Bit-perfect	Bit-perfect	Original (uncompressed)	Original (uncompressed)
Size per min (CD)	5-7 MB	5-7 MB	10.1 MB	10.1 MB
500-album library	~150-200 GB	~150-200 GB	~300-350 GB	~300-350 GB
Metadata	Excellent (Vorbis Comments)	Excellent (MP4 atoms)	Very limited	Good (ID3 tags)
Album art	Yes (PICTURE block)	Yes (covr atom)	No (without BWF)	Yes (ID3)
Max resolution	32-bit / 655 kHz	32-bit / 384 kHz	32-bit / practical limit	32-bit / practical limit
4 GB file limit	No	No	Yes (RF64 workaround)	Yes (AIFF-C workaround)
Open source	Yes (BSD)	Yes (Apache, since 2011)	N/A (public spec)	N/A (Apple spec)
Patent-free	Yes	Yes	Yes	Yes
Gapless playback	Native	Native	N/A	N/A
Streaming support	Yes (seekable)	Yes (seekable)	Not practical	Not practical

FLAC: The Universal Lossless Standard

FLAC (Free Lossless Audio Codec) is the most widely supported lossless compressed format outside the Apple ecosystem. Developed by Josh Coalson and maintained by Xiph.Org, it's open-source, royalty-free, and supported on Windows (native since 10), Android (native), Linux (native), and macOS/iOS (via third-party apps).

Compression performance: FLAC typically compresses to 50-70% of the original WAV size. Classical music with long sustained passages compresses best (~45%). Dense electronic music or heavily compressed rock compresses least (~65%). White noise barely compresses at all (~95%).

Key strengths:

Best lossless compression ratios (marginally better than ALAC)
Widest cross-platform support (everything except native Apple apps)
Excellent metadata via Vorbis Comments
Native ReplayGain support
Streaming-friendly (seekable, frame-based)
Active development and community

Key limitation: Not natively supported in Apple Music, iTunes, or iOS Music app. Apple uses ALAC for their lossless ecosystem. You can play FLAC on Apple devices through VLC, Doppler, Swinsian, or Plexamp — but not the built-in Music app.

ALAC: Apple's Answer to FLAC

ALAC (Apple Lossless Audio Codec) was developed by Apple in 2004 and open-sourced under the Apache License in 2011. It stores lossless audio in the MPEG-4 container (same container as M4A/AAC, but with lossless ALAC codec instead of lossy AAC).

Compression performance: ALAC and FLAC produce nearly identical compression ratios. In controlled tests, FLAC is typically 1-3% smaller than ALAC — a negligible difference. Both are far better than no compression (WAV/AIFF).

Key strengths:

Native support in Apple Music, iTunes, iOS, macOS, Apple TV, HomePod
Apple Music lossless tier delivers ALAC
Rich metadata via MP4 atoms (same as M4A)
Gapless playback native
Open-source since 2011

Key limitations:

Limited support outside Apple: Android supports ALAC decoding but few Android music apps prioritize it. Windows Media Player doesn't play ALAC without codecs. Linux support requires libraries.
Slightly worse compression than FLAC (1-3%)
Smaller community and fewer tools compared to FLAC

The practical decision: if your entire playback chain is Apple (iPhone, Mac, AirPods, Apple TV), use ALAC. If any part of your chain isn't Apple, use FLAC.

WAV: Uncompressed Universal

WAV (Waveform Audio File Format) stores raw PCM audio with zero compression. It's the simplest and most universally supported audio format — every device, every application, every operating system reads WAV without any decoder.

Why WAV exists in a world with FLAC:

Zero decode overhead: DAWs read WAV directly into memory without any decompression step. With 40+ tracks in a production session, this matters.
Universal tool support: Every audio editor, plugin, and hardware device supports WAV. FLAC support, while broad, isn't universal in pro audio tools.
Proven reliability: WAV has been the production audio standard since 1991. Decades of tool compatibility, no version fragmentation, no decoder bugs.

Why not to use WAV for everything:

Files are 2x larger than FLAC for identical audio
Minimal metadata support (no album art, limited text fields without BWF extension)
4 GB file size limit (RF64 extends this, but not universally supported)

Use WAV for: active production work, DAW sessions, stems. Use FLAC for: everything else (archival, libraries, sharing).

AIFF: Apple's Uncompressed Format

AIFF (Audio Interchange File Format) was developed by Apple in 1988, based on Electronic Arts' IFF format. It stores uncompressed PCM audio — functionally identical to WAV in audio quality and file size.

Differences from WAV:

Byte order: AIFF uses big-endian (Motorola convention); WAV uses little-endian (Intel convention). Modern systems handle both transparently.
Metadata: AIFF supports ID3 tags (added later), giving it better metadata than standard WAV. Album art, artist, title, and other fields work natively.
Apple tool preference: Logic Pro and GarageBand handle AIFF natively and historically preferred it. Apple Loops are AIFF-based.

In practice, AIFF and WAV are interchangeable. The audio data is identical in quality and size. Choose based on your tools: Apple audio tools slightly prefer AIFF, everything else slightly prefers WAV. Converting between them is lossless and instant — no re-encoding, just container change.

Real-World Compression Ratio Comparison

Compression ratios vary by content type. Here are real measurements across different genres (CD quality, 44.1 kHz / 16-bit stereo):

Content Type	WAV Size	FLAC Size	ALAC Size	FLAC Ratio
Classical (orchestral)	635 MB	~285 MB	~290 MB	45%
Jazz (acoustic)	635 MB	~320 MB	~325 MB	50%
Pop/Rock	635 MB	~370 MB	~375 MB	58%
Electronic (dense)	635 MB	~410 MB	~415 MB	65%
Heavy metal (compressed mastering)	635 MB	~420 MB	~425 MB	66%
White noise (worst case)	635 MB	~600 MB	~605 MB	95%

The pattern: more dynamic, more predictable audio compresses better. Classical and jazz have quiet passages, sustained notes, and wide dynamic range — highly compressible. Loudness-war compressed rock and dense electronic music are closer to random noise from a compression perspective — less compressible.

Both FLAC and ALAC follow the same pattern. FLAC is consistently 1-3% smaller across all content types — a marginal advantage.

Platform Compatibility Matrix

Platform	FLAC	ALAC	WAV	AIFF
Windows 10/11	Native	Via iTunes/codec	Native	Via player/codec
macOS	Via VLC/apps	Native	Native	Native
iOS	Via VLC/apps	Native (Music app)	Limited	Limited
Android	Native	Decode support	Native	Via player
Linux	Native	Via libraries	Native	Via libraries
Chrome/Firefox/Edge	Yes	No	Yes	No
Safari	No	Yes	Yes	Yes
Spotify	Not delivered	Not delivered	Not delivered	Not delivered
Apple Music (lossless)	Not delivered	Yes (native delivery)	Not delivered	Not delivered
Tidal HiFi	Yes	No	No	No
Amazon Music HD	Yes	No	No	No

Which Lossless Format Should You Use?

For a personal music library: FLAC. Best compression, rich metadata, widest support across non-Apple devices, active community. If you're Apple-only, ALAC.
For music production: WAV. Zero decode overhead, universal DAW support, proven reliability. Convert to FLAC for archival.
For Apple ecosystem: ALAC. Native support in Apple Music, iTunes, iOS, macOS. No third-party apps needed.
For sharing lossless files: FLAC. The recipient is more likely to have FLAC support than ALAC support (unless they're on Apple, in which case either works via third-party apps).
For long-term archival: FLAC. Open-source format with no company dependency. Will be readable in 50 years. ALAC is also open-source now, so it's also a safe archival choice, but FLAC has broader tool support for restoration and migration.

Converting Between Lossless Formats

Converting between any of these four formats is lossless — the audio data is preserved perfectly. FLAC → WAV → ALAC → AIFF → FLAC produces a file with identical audio to the original. Only metadata handling varies between tools.

The lossless format question has a simple answer: FLAC for storage and sharing, WAV for production, ALAC if you're Apple-only. All deliver identical audio quality — the choice is about ecosystem compatibility, file size, and metadata support. Don't overthink it. Pick the one your tools support best and convert freely between them as needed — every conversion is lossless.

Convert FLAC to WAV, WAV to FLAC, AIFF to WAV, or FLAC to M4A — free, lossless, at ChangeThisFile.

Key Takeaways

All four formats are bit-perfect lossless. The decoded audio is mathematically identical. "FLAC sounds different from WAV" is a myth.
FLAC and ALAC compress to 50-70% of WAV/AIFF size. FLAC is 1-3% smaller than ALAC — negligible.
FLAC: best for non-Apple, archival, and cross-platform. ALAC: best for Apple ecosystem. WAV: best for production. AIFF: Apple production variant of WAV.
A 500-album library: ~175 GB in FLAC, ~175 GB in ALAC, ~325 GB in WAV/AIFF. Same audio quality across all.
Converting between lossless formats preserves audio perfectly. Only metadata handling varies by tool.

Frequently Asked Questions

Does FLAC sound different from WAV?

No. FLAC is lossless compression — decode it and you get the exact same PCM data as the original WAV, bit for bit. You can verify this: encode WAV to FLAC, decode back to WAV, and run a binary diff. The audio bytes are identical. Any perceived difference is expectation bias, not a real acoustic difference.

Is ALAC the same quality as FLAC?

Yes. Both are lossless — they preserve every sample of the original audio perfectly. The decoded output from FLAC and ALAC (given the same source) is identical. FLAC achieves slightly smaller file sizes (1-3%), but the audio quality is mathematically the same.

Why does Apple use ALAC instead of FLAC?

Apple developed ALAC in 2004 for tight integration with their ecosystem — iTunes, iPod, iOS, and later Apple Music. It uses the same MPEG-4 container as their AAC files, making it seamless in their software stack. Apple open-sourced ALAC in 2011, but by then their entire ecosystem was built around it. There's no technical reason FLAC couldn't work — it's an ecosystem choice.

Should I keep my music library in WAV or FLAC?

FLAC. It's lossless (identical quality to WAV), half the size, and supports rich metadata (artist, album, cover art, ReplayGain). A 500-album library in WAV: ~325 GB. In FLAC: ~175 GB. Same audio, half the storage, plus proper tagging. The only reason to use WAV is for active production work in a DAW.

Can I convert FLAC to ALAC without losing quality?

Yes. Both are lossless formats, so converting between them preserves the audio perfectly. FLAC → decode to PCM → encode to ALAC produces bit-identical audio. Metadata should transfer too, though verify album art and custom fields after conversion. Tools like dBpoweramp, FFmpeg, and XLD handle this conversion well.

Which lossless format has the best compression?

FLAC, but only marginally. FLAC typically produces files 1-3% smaller than ALAC for the same audio. On a 200 GB library, that's a 2-6 GB difference — meaningful but not decisive. Both compress to roughly 50-70% of WAV/AIFF size. WAV and AIFF don't compress at all.

Why do audiophiles argue about lossless formats if they all sound the same?

Several reasons: expectation bias ("I paid more for hi-res so it must sound better"), different mastering on different releases (a hi-res FLAC may have been mastered differently from the CD version — the improvement comes from the mastering, not the format), and genuine differences in playback chains (some DACs handle ALAC and FLAC through different code paths). But the decoded PCM data from any lossless format is identical. The argument is about everything except the audio.

What about MQA — is that lossless?

No. MQA (Master Quality Authenticated) is marketed alongside lossless formats but uses lossy compression — it folds high-frequency information into the noise floor of a lower-resolution stream, which is not fully recoverable. MQA is proprietary, patented, and has been widely criticized by audio engineers for being lossy while being marketed as lossless. If you want true lossless, use FLAC or ALAC.

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