Password Strength Checker
Test how strong a password is and estimate how long it would take to crack — privately in your browser.
100% private — your password is analyzed only in your browser and never sent anywhere.
What Is the Password Strength Checker?
The Password Strength Checker estimates a password's strength from its length and character variety, calculates its approximate entropy, and shows how long it might take a fast attacker to crack. It also flags common passwords and missing character types. Your password is analyzed entirely in your browser and never sent or stored anywhere.
How It Works
Type or paste a password. The strength rating, entropy, estimated crack time and a checklist of improvements update instantly. Use Show to reveal what you typed.
When to Use It
Use it to test a password you're considering, teach good password habits, or check that a generated password is strong enough.
Frequently Asked Questions
- Is it safe to type my real password here?
- Yes — the analysis runs only in your browser with JavaScript. Nothing is transmitted over the network, logged or saved. That said, for accounts you actively use, prefer testing a similar pattern rather than the exact password.
- What is entropy?
- A measure of unpredictability in bits. More length and a bigger mix of character types increase entropy, which makes a password exponentially harder to guess.
Last reviewed: 2026-06-27