Free Password Strength Checker — Test Password Security
Instantly analyse how strong your password is — entropy, crack time, and detailed criteria breakdown. Runs entirely in your browser.
How it works
Enter your password
Type or paste a password into the input field. Use the eye icon to show or hide it.
See the strength
The strength meter updates in real time — from Very Weak to Very Strong with colour coding.
Review criteria
Check which requirements pass: length, case, numbers, symbols, and pattern analysis.
Improve it
Use the suggestions to strengthen weak passwords. Your password never leaves this tab.
Common use cases
Personal password audit
Quickly assess whether your existing passwords meet modern security standards before updating them.
Password policy compliance
Verify that new passwords meet organisation requirements for length, complexity, and uniqueness.
Security awareness training
Demonstrate to teams why short or predictable passwords are vulnerable using real entropy metrics.
Pre-submission check
Paste a candidate password before registering an account to ensure it's strong enough.
Frequently asked questions
Is my password sent to a server?
No. All analysis runs in your browser using JavaScript. Your password never leaves your device.
What does entropy mean?
Entropy measures unpredictability in bits. Higher entropy means more guesses needed to crack the password. 60+ bits is considered strong for most use cases.
What is the crack time estimate based on?
The estimate assumes an attacker using a GPU cluster at 10 billion guesses per second, which is realistic for online hash-cracking attacks.
Why does a long simple password score lower than a shorter complex one?
Length is valuable, but so is character diversity. A 20-character all-lowercase password has less entropy than a 12-character password with mixed case, numbers, and symbols.
Does the checker detect common passwords?
Yes, it checks against a short list of the most common patterns (password, 123456, qwerty, etc.) and flags them as weak regardless of length.
Can I check passwords on mobile?
Yes — the tool is fully responsive and works on all modern mobile browsers.