UtilityDeveloper

Password Generator

Generate strong random passwords with custom length and character sets. Built-in entropy strength meter and copy-to-clipboard. Everything runs in your browser.

Your password

130 bits — Excellent
Generating...
20
864

Character sets

5 alternates

Same settings, freshly generated

  • Enable at least one character set to generate.

What makes a password strong?

Strength is not about clever substitutions like turning “password” into “p@ssw0rd” — attackers know every common trick. What actually matters is entropy: the number of random binary choices baked into the secret. More entropy means a brute-force attacker has exponentially more candidates to try.

Entropy is approximated by bits = length × log2(charset size). Doubling the length doubles the bits; adding character classes only grows it logarithmically. In practice, length is the single cheapest lever — go long before you go exotic.

8 chars

52

bits of entropy

12 chars

79

bits of entropy

16 chars

105

bits of entropy

20 chars

131

bits of entropy

Assumes the full 94-character printable ASCII set (letters, digits, symbols).

Length vs character set

Entropy bits at each length and charset combination. Cells at or above 100 bits are bold — that is the rough threshold considered safe against any plausible offline attacker for the foreseeable future.

Lengthlower only(26 chars)+ upper(52 chars)+ digits(62 chars)+ symbols(94 chars)
838464852
1256687179
16759195105
2094114119131
24113137143157

Best practices

  • Use a password manager: You cannot memorize unique high-entropy strings for hundreds of accounts. A manager generates, stores, and autofills them so you only remember one master phrase.
  • Never reuse passwords: One breach on a forgotten forum becomes a breach of your email, bank, and cloud storage if the same secret protects all of them.
  • Enable 2FA wherever offered: A second factor (TOTP app, hardware key, or passkey) blocks an attacker even when the password leaks.
  • Avoid personal info and dictionary words: Pet names, birthdays, and song lyrics are the first thing targeted-attack tools try.
  • Rotate after any breach disclosure: Subscribe to a breach notifier and replace any password that appears in a public dump, even partially.
  • Length beats clever substitutions: Twenty random characters is dramatically stronger than ten characters with a sprinkling of @ and $. Spend your budget on length first.

Privacy first

Generation happens entirely in your browser using crypto.getRandomValues(). No password is sent to a server, logged, or stored by Toolsflare. Close the tab and it’s gone.