Replace real names, emails, phone numbers, and IDs with consistent placeholder values so you can share a dataset without exposing anyone. Each original value maps to the same token every time, so joins and grouping still work on the masked file. The tool saves a key file that lets you reverse the swap later — hand the anonymized data to a colleague, then re-identify records yourself when you get results back. Everything runs in your browser, so the sensitive column never leaves your machine.
Yes. The tool generates a key file that maps each placeholder to its original value. Keep that file private, and you can restore the real data anytime. Without the key, the masked file can't be reversed.
No. All masking and key generation happen locally in your browser using WebAssembly. Your file and the reversal key never get sent to any server, so it's safe for regulated or confidential data.
Yes. Each unique input maps to one fixed token, so a customer that appears 50 times becomes the same placeholder 50 times. Counts, groupings, and joins on the masked column still work.
Every tool runs entirely in your browser. Files are never uploaded — 100% private and free.