Random 6-Digit Number Generator
Why is this truly random?
This generator uses the Web Crypto API, the same cryptographic engine that secures HTTPS connections and encrypts your passwords. Unlike Math.random(), which relies on a predictable pseudorandom algorithm, crypto.getRandomValues() draws entropy from your operating system — hardware noise, interrupt timing, and other unpredictable physical sources.
The result is a number that is statistically uniform and cryptographically secure, meaning no one can predict the next value even if they know every previous one.
Use cases
- Generate a 6-digit verification or OTP code
- Create a numeric passcode for a safe or security system
- Assign random reference numbers for orders or tickets
- Generate unique employee or member IDs
- Create random seed values for games or simulations
- Pick a random lottery-style number
How it works
- Your browser generates a cryptographically secure 32-bit unsigned integer
- The integer is mapped to the range 100000–999999 using modular arithmetic
- The result is always exactly 6 digits — no leading zeros, no truncation
Everything runs locally in your browser. No data is sent to any server, and no numbers are stored or logged.
Frequently asked questions
What range does this generate?
Numbers from 100000 to 999999 — all possible 6-digit numbers. That gives you 900,000 equally likely outcomes.
Is this safe to use as a verification code?
The generation itself is cryptographically secure. A 6-digit code has 900,000 possibilities, which is the standard for two-factor authentication (2FA) and one-time passwords (OTP). Combined with rate limiting and expiration, 6 digits provides adequate security for verification flows.
Can I get numbers starting with zero?
No. This generator produces numbers from 100000 to 999999, so the first digit is always 1–9. If you need 6-digit codes with leading zeros (like 007842), use the password generator with digits only instead.
Is every number equally likely?
Yes. Each of the 900,000 possible 6-digit numbers has an equal probability of approximately 0.00011% per generation.
Probability distribution
Each number from 100000 to 999999 has an exactly equal probability of being selected. The probability of any single outcome is:
The probability of generating a specific number twice in a row is approximately 1 in 810,000,000,000 — virtually impossible even with millions of generations.
Common scenarios
Two-factor authentication
Most authenticator apps and SMS-based 2FA use 6-digit codes. This is the industry standard defined by RFC 6238 (TOTP) and RFC 4226 (HOTP). If you're building or testing a 2FA system, this generator produces realistic codes instantly.
Confirmation and tracking numbers
Airlines, shipping companies, and e-commerce platforms often use 6-digit reference numbers. They're short enough to read aloud over the phone but long enough (900,000 options) to avoid frequent collisions in moderate-volume systems.
Security codes and PINs
High-security safes, alarm systems, and access control panels often use 6-digit codes. With 900,000 possibilities, a random 6-digit PIN is 100× harder to brute-force than a 4-digit PIN.
Games and contests
Generate random entry codes, prize draw numbers, or game lobby IDs. Six digits provide enough uniqueness for events with thousands of participants.
Privacy and security
Your generated numbers never leave your device. This tool runs entirely in your browser using client-side JavaScript — no API calls, no server logs, no cookies, and no tracking of generated values. The source code is fully transparent and can be inspected in your browser's developer tools.