FormatDrop
Audio Format

FLAC

Free Lossless Audio Codec

FLAC is the preferred lossless audio format for audiophiles, music archives, and anyone who wants mathematically perfect audio at roughly half the size of uncompressed WAV. If you care about audio quality and storage efficiency, FLAC is the format of choice — with the caveat that Apple devices and iTunes don't support it natively.

What is FLAC?

FLAC stands for Free Lossless Audio Codec — 'lossless' means every bit of the original audio is perfectly reconstructed on playback, and 'free' means the format is completely open-source with no patents or licensing fees. Developed by Josh Coalson and first released in 2001, FLAC is maintained by the Xiph.Org Foundation. The codec uses linear prediction to exploit the predictability of audio signals — audio samples are predicted from previous samples, and only the prediction error (which is small for typical audio) is encoded. This is fundamentally different from lossy codecs like MP3, which permanently discard audio information. The result is files typically 40–60% smaller than uncompressed WAV with mathematically identical audio content. A 50 MB WAV of an album becomes roughly 25 MB as FLAC. FLAC supports sample rates up to 1,048,575 Hz and bit depths up to 32 bits, covering every audio specification from CD quality (44.1 kHz/16-bit) to studio master quality (192 kHz/24-bit). It also supports comprehensive metadata tags (ReplayGain, album art, lyrics, custom fields), which WAV handles poorly. FLAC playback support is excellent in the open-source and audiophile world: VLC, foobar2000, Winamp, Rockbox, all Linux audio systems, and most high-end DAPs (Digital Audio Players) support FLAC natively. The main compatibility gap is Apple: neither iTunes nor Apple Music natively supports FLAC (Apple has its own lossless format, ALAC, inside M4A containers), and FLAC doesn't play on iPhone or iPad without third-party apps.

FLAC pros and cons

Advantages

  • 100% lossless — bit-perfect reconstruction of the original audio
  • 50% smaller than WAV for the same audio content
  • Free and open-source — no licensing fees or restrictions
  • Excellent metadata support (ID3v2-like tags, ReplayGain, album art)
  • Supports high-resolution audio up to 32-bit/192 kHz
  • Native support in VLC, foobar2000, most Linux apps, and audiophile players
  • Standard format for digital music archives and high-resolution music stores

Limitations

  • Not supported natively by Apple devices, iTunes, or Apple Music
  • Not supported natively by older car stereos or many budget speakers
  • Larger than lossy formats (MP3, AAC) — typically 5× larger than MP3 at 192 kbps
  • Overkill for casual listening where lossy compression is indistinguishable

When should you convert FLAC files?

Convert WAV to FLAC for archival storage — you get lossless quality at half the file size. Convert FLAC to MP3 or AAC when you need to share audio with people who may not have FLAC-compatible players, or when file size is a concern for distribution. Convert FLAC to ALAC (M4A) if you need lossless audio on Apple devices. Never convert MP3 or AAC to FLAC — the resulting FLAC file is the same large size but contains the same lossy audio; 'lossless' only applies to losslessly encoding something that was already lossless.

Convert FLAC files

FLAC→MP3

All FormatDrop conversions run entirely in your browser — no file upload, no server processing. Your files stay on your device.

FLAC FAQ

Is FLAC really lossless?
Yes, mathematically provably. FLAC encoding is reversible: decoding a FLAC file produces bit-for-bit identical data to the original input. This is verifiable with checksums — encode a WAV to FLAC, decode back to WAV, and compare the checksums. They match. This is fundamentally different from MP3, which is a one-way lossy compression.
What's the difference between FLAC and WAV?
Both contain lossless audio, but FLAC uses lossless compression to reduce file size by roughly 50%. A 100 MB WAV album becomes about 50 MB as FLAC with identical audio quality. FLAC also has much better metadata support than WAV. The downside of FLAC is slightly more CPU usage during playback (to decompress), and narrower compatibility than WAV in some professional audio software. For general use, FLAC is strictly better than WAV — lossless quality, smaller files, better tags.
Can iPhones play FLAC files?
Not natively — iOS doesn't include a system-level FLAC codec. You need a third-party app: VLC for iOS, VOX, or Flacbox all play FLAC on iPhone and iPad. Apple's alternative is ALAC (Apple Lossless), stored in M4A containers, which plays natively in Apple Music. For listening on Apple devices, converting FLAC to ALAC (M4A) is more convenient than relying on third-party apps.

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