Aadhaar Validator
Validate Aadhaar number format online. 100% private, no data sent to any server.
Your privacy is fully protected
This tool uses the Verhoeff mathematical algorithm only. No data is sent to any server. Your Aadhaar number never leaves your browser. All computation is done locally in JavaScript.
Enter Aadhaar Number
Format: 12 digits — displayed as XXXX XXXX XXXX
How the Verhoeff Algorithm Works
The Verhoeff algorithm uses three mathematical tables — a multiplication table (d), a permutation table (p), and an inverse table (inv) — to compute a check digit.
The digits are processed right-to-left. Each digit is permuted based on its position, then combined with the running total using the multiplication table. A valid Aadhaar number produces a final result of 0.
This algorithm detects 100% of single-digit errors and all adjacent transpositions (e.g. swapping two neighboring digits).
Inverse table (inv) used in final step:
Important Disclaimer
This tool validates Aadhaar number format using the Verhoeff checksum algorithm only. A passing result does not confirm the number is issued by UIDAI or belongs to a real person. For official Aadhaar authentication, use UIDAI services at uidai.gov.in.
Privacy: Your Aadhaar number is processed entirely within your browser. Zero data is transmitted. Zero data is stored.
Aadhaar Validator कसरी प्रयोग गर्ने
- 1
Enter your 12-digit Aadhaar number in the input field.
- 2
The tool automatically formats the number as XXXX XXXX XXXX for readability.
- 3
The first digit is checked — Aadhaar cannot start with 0 or 1.
- 4
The Verhoeff checksum algorithm validates the 12th (check) digit.
- 5
A valid result confirms correct format and checksum; invalid means a digit may be wrong.
- 6
No data is ever sent to any server — all processing is in your browser.
Aadhaar Validator बारेमा
Check if your Aadhaar number is valid online. This Aadhaar validator instantly verifies the 12-digit format and check digit using the Verhoeff algorithm — the same mathematical method UIDAI uses. 100% private — your Aadhaar number never leaves your browser.
How Aadhaar validation works
Every Aadhaar number has three layers of validity: it must be exactly 12 digits, the first digit must be between 2 and 9 (UIDAI reserves 0 and 1), and the 12th digit must pass the Verhoeff checksum algorithm. This tool checks all three in real-time as you type.
What is the Verhoeff algorithm?
The Verhoeff algorithm uses three mathematical tables — a multiplication table, a permutation table, and an inverse table — to detect 100% of single-digit transcription errors and all adjacent digit transpositions. It processes the digits right-to-left, and a valid Aadhaar produces a final result of zero.
Important: format vs. authenticity
A passing result confirms the number has correct mathematical structure. It does not confirm the number is issued by UIDAI or belongs to a real person. Only UIDAI's official authentication services can verify that. This tool is useful for catching typos, data entry errors, and obviously invalid numbers before submitting forms.