No upload · No software · Runs in your browser
Compress FLAC Files
Re-encode FLAC at maximum compression for the smallest possible lossless file. FLAC is already lossless and efficient, so savings are typically 0–5% — meaningful only across large libraries. For dramatic reductions, convert FLAC to a lossy format like MP3 or Opus.
Drop your FLAC file here or click to browse
FLAC only · Max 20 MB
How it works
- 1Drop your FLAC file (up to 500 MB Pro / 20 MB free).
- 2FLAC is lossless — re-encoding gives modest savings only (0–5% typical).
- 3For dramatic size reduction, convert to MP3 (90%+ smaller) or Opus (95%+ smaller).
- 4All processing happens in your browser. Your audio never uploads.
Which quality preset to pick
FLAC re-encode (lossless, modest savings)
Re-encodes the FLAC at the default compression level. Audio is bit-perfect identical. Savings depend on whether the original was encoded at low compression — typically 0–5%.
FLAC → MP3 320 kbps (audibly transparent, ~10% size)
Lossy but indistinguishable from FLAC for most listeners on typical gear. Use [FLAC to MP3](/flac-to-mp3) for this conversion.
FLAC → MP3 192 kbps (sweet spot, ~6% size)
The bitrate at which most listeners stop being able to ABX-distinguish from FLAC. ~94% size reduction.
FLAC → Opus 96 kbps (smallest, ~3% size)
Modern codec, excellent at low bitrates. Best for web delivery and storage-constrained environments.
FLAC is already maximally compressed (mostly)
FLAC files are encoded at one of nine compression levels (0–8). Level 5 is the default. Level 8 is the maximum and gives the smallest file. The difference between levels is small in practice — typically 1–3% file size for 10–50× longer encode time. Most FLAC files in the wild are already at level 5 or 8, which is why re-encoding gives modest savings.
The audio data is identical at every compression level — FLAC is lossless. Re-encoding never changes the audio, only how efficiently it's stored on disk.
When FLAC re-compression actually helps
Three cases. First, if the FLAC was encoded by a tool that defaulted to level 0 (rare but possible), re-encoding at level 5 or 8 saves real space. Second, if you're maintaining a library at scale and 1–2% per file matters across thousands of tracks, this adds up. Third, if FLAC metadata (embedded artwork, large comments) was bloating the file, re-encoding strips unnecessary cruft.
For most users, the answer to 'how do I make this FLAC smaller' is convert it to a lossy format, not re-encode it as FLAC.
FLAC → lossy: the dramatic option
If you want a smaller FLAC, convert it to MP3, AAC, or Opus instead. Trade-offs: lossy means some audio data is discarded by the encoder's psychoacoustic model. At 192–320 kbps MP3 or 128–192 kbps AAC, the loss is inaudible to most listeners on typical playback gear. At 96 kbps Opus, voice and music are both excellent.
The right move: keep the FLAC as your archive, generate lossy copies for portable or storage-constrained use cases. Use [FLAC to MP3](/flac-to-mp3), [FLAC to AAC](/flac-to-aac), or the umbrella Opus converter for those conversions. Don't re-encode lossy → lossy if you have the FLAC source — always go FLAC → target directly.
Convert instead of compressing?
Switch formats for dramatic file-size reduction or different compatibility.
Frequently Asked Questions
Can FLAC files be compressed further?
Marginally. FLAC supports compression levels 0–8 — re-encoding at a higher level can save 1–5% file size with no audio change. Most FLACs in the wild are already at level 5 (default) or 8 (maximum), so the gains are small. For meaningful size reduction, convert to a lossy format like MP3 or Opus. Audio is bit-perfect identical regardless of FLAC compression level.
Does compressing FLAC reduce audio quality?
No. FLAC is lossless — the audio data is bit-for-bit identical regardless of compression level. Re-encoding a FLAC file produces a file with the same exact audio samples, just stored more efficiently. The only way to lose audio quality from FLAC is converting it to a lossy format (MP3, AAC, Opus, OGG).
Why is my FLAC file still huge after compression?
FLAC is lossless, so it can only compress as efficiently as the audio data allows. Sparse audio (acoustic, voice) compresses to 30–40% of WAV. Dense audio (rock, electronic, mastered loud) compresses to 55–65% of WAV. The compressor can't make audio data 'more compressible' than it inherently is. For a 50 MB MP3-equivalent FLAC, that's 200 MB of source WAV — there's no path to MP3 size while staying lossless.
Should I convert FLAC to MP3 to save space?
Only if you don't need the lossless quality on the target playback device. For phones, laptops, and casual listening, FLAC → MP3 320 kbps gives about 90% file size reduction with audibly transparent quality for most listeners. For music production, mastering, or critical listening, keep the FLAC. Best practice: keep FLAC as the archive, generate MP3 or AAC copies for portable use.
What's the smallest FLAC compression level?
Level 8 is the maximum compression. The naming is confusingly inverted — higher level number means more aggressive compression and smaller file. Encode time scales roughly 10× from level 0 to level 8 for a 1–3% file size difference. Level 5 (default) is the practical sweet spot. Level 8 is right when you're encoding once and storing forever.
Read more
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