File recovery, on the record
Your file isn’t dead.
It’s just badly zipped.
Every .xlsx, .docx and .pptx is really a ZIP full of XML. Drop one here and we’ll open it up, check every part against the official ECMA-376 schema, and show you exactly what broke — including the schema faults that AI-generated files trip over and plain XML checks never catch.

Drop the evidence here
.xlsx.docx.pptx— or click to browse
No broken file handy? Borrow one of ours:
5,342 real spreadsheets. Zero false alarms.
Every one opens in Microsoft Excel, verified by the independent xlsx-corpus-bench. So the right answer for every file is "nothing is broken".
- False alarms
- 0
- OfficeCLI: 239 on the same files.
- Files changed
- 0.32%
- 17 stale totals, fixed. Everything else comes back byte for byte.
- Fail Microsoft's validator
- 27.7%
- Yet open fine. We check against what Office does, not just the spec.
And on our 156-case fault corpus, against OfficeCLI: 133 of 133 faults found, to 100.
See the full benchmarkHow a repair runs
- 01Container
Rebuild a package whose ZIP directory is damaged
- 02XML
Close unbalanced tags and escape stray entities
- 03Package
Repair relationships and content types
- 04Schema
Element order, attribute values and references
- 05Gate
Withhold the file unless the Open XML SDK accepts it