Inspect every entry in a ZIP and see compression ratios per file plus the overall archive ratio. Spot already-compressed files that don't benefit from re-zipping.
Per-job file size, entry count, and batch caps for Ratio Calculator. Limits apply to every Archive tool in JAD Apps; upgrade for larger uploads and bigger batches.
| Tier | Max archive size | Max entries / archive | Max files per batch |
|---|---|---|---|
| Free | 47.7 MB | 500 | 1 |
| Pro | 476.8 MB | 50,000 | 20 |
| Developer | 1.86 GB | 50,000 | 20 |
Upload your ZIP archive
We parse the central directory and read uncompressed/compressed sizes per entry
Get a sorted JSON or CSV table — find which files are well-compressed and which are entropy-dense
0 bytes uploaded. Compression Ratio Calculator runs entirely in your browser using fflate, zip.js, and libarchive WASM. Your archive files never leave your device.
Text and source code: 60–85% reduction. Binary executables: 30–60%. Images/audio/video: 0–5% (already compressed). Anything below 5% means re-zipping that file is wasted CPU.
Yes — the report includes the method (Stored, Deflate, Deflate64, BZIP2, LZMA, AES) for each entry. Method 0 (Stored) entries are uncompressed, often a deliberate choice for already-compressed content.
No — they have zero size and would skew the average. The summary row reports total entries (excluding directories), total uncompressed, total compressed, and the overall ratio.
Run DEFLATE levels 1, 3, 6, and 9 on your files and see size vs time trade-offs side-by-side. Find the sweet spot for your data, runtime, and bandwidth budget.
Open toolBreak down a ZIP by file type and folder. See which extensions dominate the archive and where the bulk lives. Helps identify low-value bloat. Bar chart included.
Open toolGroup every entry in an archive by file extension and see counts plus uncompressed and compressed totals. Find dominant file types and dead weight.
Open tool