Mask Credit Card Numbers in a File Find card numbers in a CSV or Excel file and mask them, keeping only the last 4 digits. Free, private, no upload.
Quick answer: Hide sensitive values before sharing data.
Related: Data Masking and Anonymization · Mask Emails in a CSV File · Anonymize CSV Data · Mask PII in Excel Files · Data Privacy Guides and Free Tools
How to use the Mask Credit Card Numbers in a File Hide sensitive values before sharing data.
Data Masking hides personal data before you share a file. It detects columns that look like emails, phones, names, addresses and card numbers, suggests a method for each, and previews the result. Choose fake data, partial masking, hashing, noise, rounding or removal. Consistent masking gives the same output for the same input, so related files still line up. Your data stays in your browser.
Load your data Check the suggested methods Preview and download Tips Personal data (email, phone, names…) is detected automatically. Consistent masking gives the same result for the same input. Add a salt to make hashed values harder to guess. Example Input: 4111 1111 1111 1111
Output: **** **** **** 1111
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Frequently asked questions Does it detect card numbers by itself? It flags columns that look like card numbers and suggests a method. Check the preview before you download.
Is masking the same as anonymizing? Not always. Combined details can still identify people, so review before sharing.
Can a hash be reversed? Not directly, but easy-to-guess values can be matched. Use a salt.
How does Data Masking protect personal data? It finds columns that look like emails, phones, names or card numbers, and lets you choose a method for each: fake data, partial masking, hashing, noise, rounding or removal. The same input can give the same output, so relationships between files still line up.
Can I prove a file was masked? Yes. Save the masked file to Recent files and open Data Lineage. It lists every masked column and the method used.
Related pages Data Masking and Anonymization : Find and hide personal data (emails, phones, names, card numbers) in CSV, JSON or Excel files before sharing. Runs in your browser; nothing is uploaded.Mask Emails in a CSV File : Hide email addresses and phone numbers in a CSV file before you share it. Detects personal columns for you. Free, in your browser.Anonymize CSV Data : Anonymize a CSV before sharing it: hide names, emails, phones and card numbers with the method you choose. Free, in your browser.Mask PII in Excel Files : Find and hide personal data in an Excel file before you share it, such as emails, phone numbers and names. Free, in your browser.Mask Phone Numbers in a CSV : Hide phone numbers in a CSV, Excel or JSON file before you share it. Keep the country code or last digits, or replace with fake numbers. Runs in your browser.Mask Names in a CSV File : Replace real names in a CSV, Excel or JSON file with fake names or initials, so you can share the data safely. Free, in your browser.Hash Columns in a CSV File : Hash email addresses, IDs or any column in a CSV so values stay matchable but unreadable. Free, in your browser, nothing uploaded.Pseudonymize Data Online : Pseudonymize personal data: replace direct identifiers with consistent fake values so records stay linked. 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