All The Validators logoAll The Validators

security validator

Password Entropy Calculator

Estimate password entropy (bits) in-browser to see how length and character sets impact strength.

Results

Processing…
Strength
Processing...
Entropy
Processing...
Guidance
Processing...

How to use this validator

  1. Enter a test password (avoid production secrets).
  2. Review entropy in bits plus guidance.
  3. Increase length or add character sets to raise entropy.

Rules & checks

Calculates entropy from length × character-set size (lowercase/uppercase/digits/symbols).

Flags low entropy when below common guidance (~60 bits).

Heuristic math only; no breach list checks; fully client-side/offline.

Inputs explained

  • Password

    Use a test or placeholder password. Avoid real secrets; longer phrases with mixed sets increase entropy.

When to use it

  • Explain to users why longer passphrases help
  • Compare generated passwords from different tools
  • Quickly sanity-check internal password policies

Common errors

  • Short length even with symbols
  • Relying on common patterns that entropy math can’t detect
  • Using only one character class (all lowercase)

Limitations

  • Entropy math is heuristic; it does not detect common/breached passwords.
  • Does not enforce site-specific rules.
  • Do not paste production credentials; use test strings.

Tips

  • Long passphrases (4–5 words) often beat short complex strings.
  • Mix cases, numbers, and symbols to increase charset size.
  • Pair with breach checks and a password manager for real security.

Examples

High entropy

  • LongPa$$phrase2024 -> ~78 bits

Lower entropy

  • Password1 -> ~34 bits

Deep dive

This password entropy calculator estimates bits of entropy from length and character variety to show how resilient a password is to guessing.

It runs locally for privacy; combine it with breach checks and password managers for real-world protection.

FAQs

Is this a breach check?
No. It only estimates entropy. Use breach-check services for real passwords.
Is my password uploaded or stored?
No. Everything stays in your browser and clears on refresh.
Does higher entropy guarantee safety?
No. It’s an estimate. Avoid common passwords and reuse; rely on password managers and breach checks.

Related validators

security

Password Strength Checker

Score password strength with clear, local checks—length, variety, and guidance without sending data anywhere.

security

API Key & Token Validator

Check common API key/token formats (Stripe, GitHub, AWS, OpenAI, etc.) locally.

security

JWT Signature Validator (HS256)

Validate HS256 JWT signatures with a shared secret, fully client-side—no tokens or secrets ever leave your browser.

security

Credit Card Validator

Run a local Luhn check to confirm card number format before hitting payment APIs—no data leaves your browser.

developer

Regex Tester

Test regex patterns against sample text with live matches and errors.

All entropy calculations happen in your browser. Nothing is sent, logged, or stored.

Heuristic estimate only. Do not paste production credentials.