Understand the lock.
Choose the right recovery.
Original tests. Downloadable samples. Clear limits. A practical laboratory for PDF, Excel and ZIP password problems.
OPEN PASSWORD / SHEET / STRUCTURE
SAME EXTENSION. DIFFERENT REVISIONS.
FORMAT / TOOL LIMIT / VALIDATION
A file extension is a starting point, not a diagnosis.
Start with what the file is asking you to do.
Workbook package parts unchanged in our worksheet-unprotect test.
See exactly what changed ↗Research lab
Research articles are currently available in English.
Excel password remover online: first identify what is actually locked
Five downloadable Excel test files show the difference between an opening password, worksheet protection and workbook structure protection. Includes a private, browser-only XLSX inspector.
Read the experiment ↗EXPERIMENT / 02 · Excel integrityHow to unprotect an Excel sheet: what changed in our integrity test?
A worksheet-unprotect test with formulas, formatting, a chart, merged cells and validation. See the two changed XML parts, twelve unchanged parts and the limits of the check.
Read the experiment ↗EXPERIMENT / 03 · PDF benchmarkPDF password recovery time: R3, R4, R5 and R6 tested on one RTX 4060
Known-password controls and short numeric-mask tests on generated PDF files. Compare measured candidate rates, the failed R2 control and a clearly labeled time estimator.
Read the experiment ↗EXPERIMENT / 04 · ZIP positive controlsLong ZIP password recovery: when a correct dictionary still reports no result
Five owned ZipCrypto samples with 31, 32, 51, 52 and 127-character known passwords expose a version-specific tool limit. Includes downloads, controls and a false-positive check.
Read the experiment ↗Show the work.
01 / RepeatablePublic fixtures, known test passwords and SHA-256 fingerprints.
02 / SpecificVersions, protection types and measured conditions accompany results.
03 / HonestFailed controls and untested cases stay visible. No invented success rates.