Question 1

What is PII masking?

Accepted Answer

PII (Personally Identifiable Information) masking replaces sensitive data such as email addresses, phone numbers, credit card numbers, and IP addresses with masked characters. This allows you to share logs, screenshots, or documents without exposing private information. The original data is never transmitted — all masking happens locally in your browser.

Question 2

Which patterns does the String Obfuscator detect?

Accepted Answer

The tool detects five built-in patterns: email addresses (RFC 5322 local-part + domain), credit card numbers (13–19 digits with optional spaces or dashes), phone numbers in E.164 and common national formats, IPv4 addresses, and JSON Web Tokens (JWT). You can also supply your own custom regular expression to mask arbitrary patterns.

Question 3

Is my data sent to a server?

Accepted Answer

No. All masking is performed client-side using JavaScript regular expressions. Your input text never leaves your browser, making this tool safe for use with sensitive production data, logs, and confidential documents.

Question 4

Can I use a custom regex to mask my own patterns?

Accepted Answer

Yes. Enter any valid JavaScript regular expression in the Custom Regex field. The tool applies it globally across the input and counts matches alongside the built-in patterns. Invalid patterns are silently ignored so they do not interrupt your workflow.

các công cụ miễn phí dành cho lập trình viên web

String Obfuscator / PII Masker

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Output