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Password Generator

Create strong random passwords & passphrases, evaluate strength, and export results. Works offline • Share link • Download • Print/PDF

Generate & Check

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Generated Passwords

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Automated Tests

Basic checks for character class coverage, ambiguity removal, and entropy monotonicity.

How to Build Strong Passwords and Passphrases (with a Free Generator)

Table of Contents
  1. Why strength matters
  2. Password vs passphrase
  3. Entropy and crack time, explained
  4. Best practices for everyday users
  5. How to use this generator
  6. FAQ

1) Why strength matters

Your accounts are only as strong as the secrets that protect them. Attackers don’t “guess” like people; they try billions of guesses per second with optimized hardware and clever dictionaries. Randomness and length are the antidote. This page lets you make both.

2) Password vs passphrase

A password is a string of characters (letters, digits, symbols). A passphrase is multiple random words—often easier to remember while remaining strong. If each word is chosen uniformly from a dictionary of D words, the entropy grows by log₂ D per word. Four words from a 2048‑word list already exceed 44 bits; six words exceed 66 bits, before any extras like capitalization or separators.

3) Entropy and crack time, explained

Entropy is a way to talk about uncertainty. If a password is chosen uniformly from R symbols and has length L, an attacker must try, on average, half of the R^L space. We display the resulting entropy and an estimated time to crack based on the speed you pick. These are optimistic for attackers; rate limits, 2FA, and server‑side hashing push the real risk even lower.

4) Best practices for everyday users

5) How to use this generator

  1. Pick Generator or Passphrase, then adjust options.
  2. Click Generate to produce multiple candidates.
  3. Copy your favorite and store it in a password manager.
  4. Use Strength Check to estimate entropy and crack time.
  5. Download results as a text file or print to PDF if you need a record.

6) FAQ

Do you send my passwords anywhere?
No. Everything runs locally, inside your browser tab. Close the tab and the data is gone.
What is an “ambiguous” character?
Characters that are easy to confuse visually (like O and 0, or braces and brackets). You can exclude them with one click.
What length should I choose?
For random passwords, 16 is a sensible minimum for long‑term use. For passphrases, use at least 4 random words, ideally 5–6 for critical accounts.

This tool is for education and personal use. It makes no claims about specific websites’ password rules.