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Strong Password Generator

Generate random, cryptographically secure passwords with custom character sets, entropy, and length.

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About this Strong Password Generator

The Strong Password Generator creates high-entropy, randomized passwords meeting enterprise security compliance standards to protect against brute-force attacks.

Transparent calculation methodology
Editorial review: CalculatorAll.online Editorial TeamLast reviewed: August 29, 2026

How this calculation works

The Strong Password Generator creates high-entropy, randomized passwords meeting enterprise security compliance standards to protect against brute-force attacks.

Mathematical formula and logic

Password Entropy (bits) = Length × log2(Pool Size). A 16-character password with 94 characters has ~105 bits of entropy.

Worked example

A 16-character password using uppercase, lowercase, numbers, and symbols generates 105.1 bits of entropy, taking trillions of years to brute force on supercomputers.

Calculation assumptions

  • Uniform pseudorandom selection across character pools.
  • Passwords are generated locally in the browser memory and never transmitted over the network.

Frequently asked questions

What is a strong password entropy score?

Entropy above 80 bits is considered very strong for online accounts; entropy above 100 bits provides military-grade resilience against offline dictionary and brute-force attacks.

How long does it take a computer to crack an 8-character password?

An 8-character password containing only lowercase letters can be cracked in less than a few minutes with modern GPU clusters. Increasing length to 16 characters raises crack time to millions of years.

Are passphrases better than passwords?

Yes, passphrases combining 4 to 6 random words (e.g. 'correct-horse-battery-staple') offer high entropy while remaining easy for humans to memorize.

Is this password generator safe?

Yes, all passwords are generated purely client-side within your local browser JavaScript runtime. Nothing is logged, cached, or transmitted to any server.

What are ambiguous characters?

Ambiguous characters are glyphs that look nearly identical in many fonts, such as uppercase 'I', lowercase 'l', number '1', number '0', and letter 'O'.