SSN Masker
Mask a US Social Security Number to safely show only the last four digits — ideal for display and logging contexts.
100% client-side · no upload
Masked (standard)
Masked (X digits)
Last 4 only
How to use
- Enter a SSN in XXX-XX-XXXX or plain 9-digit format.
- Three masked variants appear instantly: standard dashes, X-replaced digits, and last-4-only.
- Use the appropriate format for your display or logging need.
Related format tools
- Credit Card Formatter — format card numbers with standard spacing
- Phone Number Formatter — format phone numbers into E.164 and national styles
- Name Formatter — format personal names into full name and initials
常見問題
- Is the SSN masker free?
- Yes, completely free with no signup and no usage limits.
- Does my SSN leave my device?
- No. All masking runs in JavaScript inside your browser. Nothing is sent to any server.
- Does it work on mobile?
- Yes. The tool is mobile-first and works on iPhone Safari and Android Chrome.