The Password Strength Checker analyses any password and rates its resistance to guessing. It estimates entropy in bits, calculates how long an offline attack would take, and shows a clear checklist of the criteria your password meets — all without sending the password anywhere.
How password strength is measured
Strength comes down to entropy — the number of equally likely possibilities an attacker must search. This tool estimates entropy from the password's length and the size of its character pool (lowercase, uppercase, digits and symbols), then converts that into an estimated offline crack time at roughly 10 billion guesses per second.
It also penalises common passwords and obvious patterns like repeated characters or sequences (abc, 123, qwerty), which real attackers try first.
What makes a strong password
- Length matters most — aim for 12+ characters, ideally 16 or more
- Mix character types: lowercase, uppercase, numbers and symbols
- Avoid dictionary words, names, dates and keyboard patterns
- Use a unique password for every account
- A passphrase of 4+ random words is both strong and memorable
Is it safe to type my password here?
Yes. The analysis runs entirely in your browser with JavaScript. Your password is never transmitted to a server, logged or stored — close the tab and it is gone.
Related searches
Recommended Security, Hash & Crypto tools
Explore more free online tools related to Password Strength Checker.
Passphrase Generator
Generate strong, memorable passphrases from random words (diceware-style) with adjustable length, separators and extras.
AES Text Encrypter / Decrypter
Encrypt and decrypt text with AES-256-GCM and a password, right in your browser. Share secrets safely over any channel.
Email Validator
Check whether an email address is valid — verify syntax, structure, TLD and flag disposable or role-based addresses.
Credit Card Validator
Validate a credit card number with the Luhn algorithm and detect its brand (Visa, Mastercard, Amex and more).
Random PIN Generator
Generate secure random numeric PINs of any length using a cryptographically strong random generator.
Secure Random Token Generator
Generate cryptographically secure random tokens — API keys, secrets and salts — in hex, Base64 URL or alphanumeric.