Repair a Damaged ZIP: Recover Verified Files Locally
Recover intact stored or deflated files from a damaged ZIP, verify CRC-32, rebuild a new archive and download a clear file-by-file evidence report.
Archive Triage
Files remain local. Only actual checksum-verified members enter the new ZIP; missing bytes are never invented.
Supported scope: 64 MiB input · 24 MiB/member · 96 MiB decode · 2,000 members
Original ZIP archive
Required fields are marked with an asterisk.
Verified recovery and exclusions
Review your output, then save it to your device.
Make the next step clear.
Your findings, assumptions and next steps will appear here after you run the check.
Archive Triage · https://archive.kitforma.com/ · KitForma
Recover intact members despite a missing ZIP directory
Choose verified files and rebuild a real ZIP
CRC, SHA-256 and explicit exclusion evidence
Understand the evidence.
Focused guides explain the rules, the edge cases and the checks worth doing before you act.
Recover verified files from a damaged ZIP
Understand when intact member bytes can be repackaged, and when a damaged archive cannot supply them.
Read the guide ↗Field guide / 02Understand ZIP CRC errors and recovery limits
Separate a broken index from damaged payloads, unsupported encodings and unsafe recovery assumptions.
Read the guide ↗Field guide / 03Export selected recovered files with a clear evidence trail
Choose verified members, understand path changes and keep a useful inventory alongside the output.
Read the guide ↗Before you start
Does this really repair a ZIP?
It salvages verified intact member bytes and writes a real new ZIP. It can help when directory records are missing or some members are damaged. It does not recreate lost bytes or guarantee that every original file survives.
Are failed CRC files included anyway?
No. A member must pass declared-length and CRC-32 checks plus supported format, size and path checks. Failed, truncated, encrypted and unsafe-path members are excluded from the verified ZIP.
Why might scanning stop before the end?
Without an intact central directory, unknown data-descriptor sizes or a damaged local header make the next member boundary ambiguous. The tool stops and reports that point instead of guessing inside compressed data.
Which formats and filename encodings work?
Ordinary single-file ZIP with stored or deflated members, UTF-8 or CP437 filenames and supported Unicode path extra fields. ZIP64, encryption, multi-disk ZIP, self-extracting files, RAR, 7z and PAR2 are unsupported.
Are files uploaded or opened as web pages?
No. Analysis and rebuilding use local browser memory. Inventory names are inactive text and recovered HTML or scripts are not executed. Downloaded files still need appropriate review before you open them.
What are the size limits and metadata changes?
64 MiB source, 24 MiB per member, 96 MiB cumulative attempted decode and 2,000 members. A 200:1 ratio bound applies above one MiB. Output has fresh ZIP metadata; original times, comments, permissions and signatures are not restored. Collision renames are recorded, and the original is downloadable unchanged.
Sources & assumptions
Formats, algorithms and supported features are documented below. Check the stated scope and inspect your output before using it.
- PKWARE ZIP file format specification ↗
Primary structure, compression, CRC, descriptor and filename-encoding reference. The product supports a bounded subset.
- fflate official project ↗
Self-hosted MIT JavaScript deflate and ZIP implementation; streaming decode is bounded before verified output is retained.
Reviewed 2026-10-17. Read our methodology or report an issue.