Question 1

What is data masking?

Accepted Answer

Data masking is the process of replacing sensitive or personally identifiable information (PII) with fictitious or anonymized values. It is commonly used to protect privacy when sharing logs, test data, or documents containing real user data.

Question 2

What types of data can this tool mask?

Accepted Answer

The tool can mask email addresses, phone numbers, credit card numbers (preserving the last 4 digits), IPv4 and IPv6 addresses, and common date formats. You can also define your own regex pattern with a custom replacement string.

Question 3

Is my data sent to a server?

Accepted Answer

No. All masking is performed entirely in your browser using JavaScript regular expressions. Your text never leaves your device, which makes this tool safe for sensitive production data and GDPR compliance workflows.

Question 4

Can I customize the masking character?

Accepted Answer

Yes. By default the tool uses an asterisk. You can change the mask character to any character you prefer, such as X, #, or a space. The custom replacement field for custom regex rules accepts full replacement strings.

Question 5

How does credit card masking work?

Accepted Answer

The tool detects sequences of 13 to 16 digits optionally separated by spaces or hyphens, replaces all but the last 4 digits with the mask character, and formats the result as **** **** **** 1234. This matches the display format used by most payment systems.

Data Masking / Redaction Tool

Frequently Asked Questions