Compression ratio

Computes the compression ratio (size before ÷ size after) and the percentage reduction — from file size before and after compression (in bytes).

Input data

Results

Enter data and click Calculate.

Często zadawane pytania

When should I use compression ratio?
When comparing before/after sizes (gzip, Brotli, Zstd) or planning storage and transfer.
What does a high ratio mean?
Stronger compression (fewer bytes after). Often costs more CPU — measure time too.
What values are realistic?
Text/HTML often 3–10:1; random or already-compressed data ≈ 1:1.
What looks “bad”?
After size larger than before (bad inputs) or ~1:1 with no real gain.

How the results are calculated