Protect spreadsheet data
Replace sensitive values with consistent identifiers and restore them later.
XLSX or CSV - up to 10 MiB. Drag a file here or choose it from your device.
Supported files and limits
10 MiB per input file; 40 MiB expanded XLSX; 512 ZIP entries; 20 sheets; 20,000 rows per sheet; 200 columns; 200,000 cells per workbook; 8,000 characters per cell; 50,000 correspondences; 1,000,000 combined characters for original and distinguishing values in a recovery project; 8 MiB per recovery file.
XLSM, XLS, encrypted, digitally signed, protected or incompatible workbooks are rejected. Formulas and macros are never executed. Missing stored formula results are rejected.
Matches are exact and case-sensitive. Spaces and accents are preserved; similar spellings are never merged. Replacement and restoration apply to complete cells, not fragments of text.
Your documents, cells, correspondences and passwords are processed in this browser. They are not uploaded or saved automatically. Closing or resetting this tool clears its working session.
XLSX/CSV: 10 MiB, 20 sheets, 20,000 rows per sheet, 200 columns, 200,000 cells and 8,000 characters per cell. Recovery file: 8 MiB.
How to prepare a spreadsheet and recover its values
- Choose an XLSX or CSV. Review every sheet and select the columns, rows or values to replace.
- Review proposals and choose a password. Download the private recovery file separately, then the prepared copy.
- To recover values, choose the processed file and recovery file. Review issues and download the result.
Which file can I share?
The prepared copy contains the identifiers you reviewed. Keep the encrypted recovery file and its password separately. Without both, we cannot recover values.
Does this anonymize data?
This is reversible pseudonymization. Other values or combinations may still identify someone. Review unselected values and the intended use before sharing.
What happens to Excel formulas and formatting?
A new values-only workbook is generated. Formulas become their stored results, without recalculation; those results may be stale. Full styling, comments, links, charts, pivot tables and properties are not preserved. All included sheets become visible with generic names. Files without usable results or with incompatible protections are rejected.
Are external changes preserved?
Yes, within supported limits: only cells containing a complete known alias are replaced. Sorted, duplicated or filtered rows and added columns are retained. Modified, foreign-project or missing aliases are never reconstructed by guessing.
How are values detected?
Whole-cell rules suggest emails, phone numbers, DNI/NIE with check letters, and IBANs with length and modulo 97 validation. They can miss values or propose false positives. Names, companies and references require explicit selection or exact lists. Case, spaces and accents are not normalized. Unselected numbers are preserved; unformatted integers can be selected as phones or references.
Is anything sent or saved?
Files, passwords and mappings are processed in a browser worker. They are not sent to services or saved automatically. Offline use is not guaranteed.
Recovery format and technical limits
Need to check a download?
Calculate the final file’s fingerprint to compare it later.
Calculate SHA-256