Mask Excel & CSV data
Replace names, phone numbers and emails on your device before sharing a spreadsheet with AI.
Drop an Excel / CSV file here
or choose a file from your device
No AI analysis. No data sent to AI.Detection uses column names and text patterns. Files and answers stay on your device.
Try it with a sample
Explore the workflow with fictional customer data.
| Field | Original value | AI-ready value |
|---|---|---|
| Name | Alex Morgan | PERSON_001 |
| Phone number | +1 (202) 555-0142 | Leave blank |
| Revenue | 86,000 | 86,000 Keep the number |
The same name gets the same token. Keep numbers such as revenue and visits for analysis.
Output IDs are omitted in this example. Actual tokens include an output ID to prevent restoration with an unrelated mapping.
Frequently asked questions
A few things to know before you start.
Is it free?
Every feature is free. No account, credit card or AI API key is required.
Are my files sent anywhere?
Files and pasted answers are processed only in your browser. There is no upload or autosave. Loading the website requires a connection.
Are Excel formulas and formatting preserved?
The output is a new, values-only table for AI analysis. Saved formula results are used; formatting, comments, links and images are omitted. Hidden sheets are excluded. Your original stays unchanged.
Can I restore masked information?
Values replaced by tokens can be restored in AI answers using the mapping. Deleted values, omitted address details and dates converted to ages cannot be restored.
What if my CSV text looks garbled?
Encoding is normally detected automatically. If text looks wrong, select an encoding under “Fix garbled CSV text” and reopen the file. Try Windows-1252 for older Western European CSVs.
Does my work survive closing the browser?
Reloading or closing the tab discards loaded data and unsaved mappings. To restore answers later, save the encrypted mapping along with the AI-ready file.