concept
Lossless compression
Compression that reconstructs the original data bit for bit when decoded.
Convert a file nowLossless compression explained
Lossless algorithms find and remove statistical redundancy — repeated byte sequences, predictable pixel neighbours, silence in audio — and record a shorter description of the same data. Decoding replays that description and reproduces the input exactly.
Because nothing is thrown away, a lossless file can be re-saved indefinitely without degrading. The trade-off is size: lossless photographs are typically several times larger than a lossy equivalent at visually similar quality.
PNG, FLAC, ZIP and TIFF (with LZW or Deflate) are lossless. JPEG, MP3 and AVIF at default settings are not.
Where you meet it
- PNG images
- FLAC audio
- ZIP archives
- Deflate-compressed PDFs
Lossless compression scores
Deterministic scores calculated from the structured facts above. Identical facts always produce identical scores.
Overall score
100/100
Archiving score
100- it is a current, actively maintained format
- it is actively maintained and current
Confidence 33% · evidence coverage 56%
Longevity score
100- it is actively maintained and current
- it is a current, actively maintained format
- it sits at the centre of the format ecosystem, with many documented relationships
Confidence 35% · evidence coverage 75%
Related to Lossless compression
Frequently asked questions
Does lossless compression reduce quality?
- No. The decoded output is identical to the input, so quality is unchanged no matter how many times you re-save.
Data quality
Every claim on this page is classified as a verified fact, a derived fact or an assumption.
- Overall confidence
- 85%
- Verification status
- verified
- Last reviewed
- 2026-08-03
- Verified facts
- 1
1 classified claim backed by 1 source.
- Convert Always editorial review — Convert Always
Sources and review status
Review status: verified · confidence 85%
Last reviewed 2026-08-03 (revision 1).
- Convert Always editorial review — Convert Always