Utilities

How Strong Is Your Password? Entropy, Crack Time, and How to Generate Safer Ones

Learn what makes a password truly strong, understand entropy and crack-time estimates, and generate cryptographically random passwords — all in your browser.

Published 2026-04-19 · 6 min read

Why "Password123" Is Gone in 0.001 Seconds

Modern GPU-based password cracking rigs attempt over 1 billion guesses per second. A simple 8-character lowercase password has around 200 billion combinations — cracked in under 4 minutes. Add uppercase, digits and symbols, and the math changes dramatically.

What Is Password Entropy?

Entropy (measured in bits) represents how unpredictable a password is. A password drawn from a pool of N characters and L characters long has entropy = L × log₂(N) bits. More bits = more combinations = harder to crack.

  • Under 28 bits — Very Weak: cracked instantly
  • 28–40 bits — Weak: minutes to hours
  • 40–60 bits — Fair: days to weeks on a consumer GPU
  • 60–80 bits — Strong: years to decades
  • 80+ bits — Very Strong: millions of years

Generating a Strong Password

Rafiqy's Password Generator uses crypto.getRandomValues() — your browser's cryptographically secure random number generator, the same standard used by security software. Set your length (6–64 characters) and toggle which character types to include.

A 16-character password using all four character types achieves 95+ bits of entropy — that's over a million years to crack at 1 billion guesses per second.

Test Your Own Password

Use the Test your own password section to check any password you already use. It runs entirely in your browser — nothing is ever sent to a server. You'll see the entropy score, strength label, and realistic crack-time estimate in real time.

Quick Rules for Strong Passwords

  1. Use at least 16 characters
  2. Mix uppercase, lowercase, digits and symbols
  3. Never reuse passwords across accounts
  4. Use a password manager to remember them

Generate a strong password or test your existing one — 100% private, nothing leaves your browser.

Open Password Generator →

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