Verify every entry in a ZIP against its stored CRC32 checksum to detect corruption, partial downloads, or tampering. Browser-native, zero upload.
Per-job file size, entry count, and batch caps for Integrity Tester. 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 |
Drop your ZIP archive
fflate decompresses each entry and compares its computed CRC32 to the stored value
Get a per-entry pass/fail table with a summary count of corrupt files
0 bytes uploaded. Archive Integrity Tester runs entirely in your browser using fflate, zip.js, and libarchive WASM. Your archive files never leave your device.
Either the archive was truncated during transfer, the storage media has bit rot, or the file was tampered with. CRC32 is not a security hash — for tamper detection use the Checksum Generator (SHA-256) over the source files.
Yes — provide the password and the integrity test reads through decryption. AES-256 entries store CRC32 over plaintext, so a bad password manifests as a CRC32 failure.
TAR has no per-entry checksum — only a header checksum. 7Z stores CRC32 like ZIP. For TAR, verify the outer GZIP CRC32 (which fflate reports) and the SHA-256 of the whole .tar.gz instead.
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.
Open toolCompute SHA-256 (or MD5, SHA-1) for every entry inside a ZIP and export the manifest as CSV or .sha256sums. Tamper-evident, audit-ready, browser-native.
Open toolScan a damaged ZIP byte-by-byte for surviving local file headers and recover every readable entry into a fresh ZIP. Last-resort recovery, browser-native.
Open tool