Best Free Online Developer Tools to Use in 2026
A practical, opinionated list of the best free online developer tools worth using in 2026, organized by category so you can find what you need fast.
Aug 08, 2026
SSN Validator
Validate US Social Security Number format with area, group, and serial number validation.
SSN Validator
Enter a 9-digit SSN with or without hyphens (e.g. 987-65-4321 or 987654321).
Area
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Group
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Serial
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Region
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- Enter SSN — Type the 9-digit Social Security Number (with or without hyphens).
- Instant validation — See format validation, area number check, group number range, and serial number verification.
- Region info — The area number reveals which state or region the SSN was issued in.
What Is a Social Security Number?
A Social Security Number (SSN) is a 9-digit identifier assigned to U.S. citizens, permanent residents, and temporary workers. It was created in 1936 as part of the Social Security Act and is used for tax reporting, employment verification, and government benefits.
The SSN format is AAA-GG-SSSS where:
- Area Number (AAA) — 001-899 (excluding 666, 000). Originally based on geographic region.
- Group Number (GG) — 01-99. Used to further classify numbers within an area.
- Serial Number (SSSS) — 0001-9999. A unique sequential number.
SSN Area Number Reference
| Area Range | Region / State |
|---|---|
| 001-003 | New Hampshire |
| 004-007 | Maine |
| 008-009 | Vermont |
| 010-034 | Massachusetts |
| 035-039 | Rhode Island |
| 040-049 | Connecticut |
| 050-134 | New York |
| 135-158 | New Jersey |
| 159-211 | Pennsylvania |
| 212-220 | Maryland |
| 221-222 | Delaware |
| 223-231 | Virginia |
| 232-236 | West Virginia |
| 237-246 | North Carolina |
| 247-251 | South Carolina |
| 252-260 | Georgia |
| 261-267 | Florida |
| 268-302 | Ohio |
| 303-317 | Indiana |
| 318-361 | Illinois |
| 362-386 | Michigan |
| 387-399 | Wisconsin |
| 400-407 | Kentucky |
| 408-415 | Tennessee |
| 416-424 | Alabama |
| 425-428 | Mississippi |
| 429-432 | Arkansas |
| 433-439 | Louisiana |
| 440-448 | Oklahoma |
| 449-467 | Texas |
| 468-477 | Minnesota |
| 478-485 | Iowa |
| 486-500 | Missouri |
| 501-502 | North Dakota |
| 503-504 | South Dakota |
| 505-508 | Nebraska |
| 509-515 | Kansas |
| 516-517 | Montana |
| 518-519 | Idaho |
| 520 | Wyoming |
| 521-524 | Colorado |
| 525-527 | New Mexico |
| 528-529 | Arizona |
| 530-531 | Utah |
| 532 | Nevada |
| 533-534 | Washington |
| 535-539 | Oregon |
| 540-544 | California |
| 545-573 | California (continued) |
| 574 | Alaska |
| 575-576 | Hawaii |
| 577-579 | District of Columbia |
| 580 | Puerto Rico |
| 581-584 | Puerto Rico (continued) |
| 585-586 | Guam |
| 587-588 | American Samoa |
| 589-590 | U.S. Virgin Islands |
| 691-699 | Not used / Reserved |
| 700-728 | Railroad Retirement Board |
| 729-733 | Enumeration at Entry |
| 734-749 | Not used / Reserved |
| 750-772 | Not used / Reserved |
| 773-899 | Not used / Reserved |
What is the SSN format?
The SSN format is AAA-GG-SSSS — a 3-digit area number, a 2-digit group number, and a 4-digit serial number. It is commonly written with hyphens but can also be entered as 9 consecutive digits.
What area numbers are invalid?
Area numbers 000, 666, and 900-999 are invalid. The SSA has never issued numbers in those ranges.
Can I verify if an SSN is actually issued?
This tool validates format only. For actual issuance verification, you need to use the Social Security Administration's verification services or the E-Verify system.
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