Password Strength Checker
Type a password and see its strength estimated on the spot from length, character variety and entropy — plus what to fix. Your input is never sent anywhere; the evaluation happens entirely in your browser.
Your password never leaves the page. Everything is evaluated in your browser.
How to Use the Password Strength Checker
Click one of the Examples (click to try) chips above the field to drop a sample straight into the input and see the strength bar and rating update instantly. When you type your own password, the strength bar and rating (Very weak to Very strong), along with the character count, character types and estimated entropy, are judged live on every keystroke — there's no button to press. Use the tips to shape a stronger password. Your input is never sent anywhere; the evaluation happens entirely in your browser.
Here's a concrete example of why length, character variety and dictionary words change the strength so much. The password password (8 characters, lowercase only, a dictionary word) is a common word on its own, so it's cracked instantly and rated "Very weak." Dressing it up as Pa$$w0rd! with symbols and digits barely helps, because the original word still shows through. A passphrase such as correct-horse-battery-staple is 28 characters long, but this tool counts words, not characters: even if the words were chosen at random it is only four of them — about 26 bits at the 6.5 bits per word this tool assumes. That particular string is also the well-known XKCD example, so it is flagged as a common phrase and rated "Weak". Picking words nobody has published still leaves you at 26 bits for four words, so a passphrase needs more of them. What counts is not visible length but how many ways the password could have been built — Kp7aQ2mZ9rTbX4nL, sixteen characters picked by a machine, comes to about 95 bits and "Very strong". To make a passphrase work, use ten or more words, or let a generator pick them.
- Length: Length matters most. Aim for at least 12 characters, ideally 16 or more.
- Character types: Mixing lowercase, uppercase, digits and symbols widens the brute-force space.
- Estimated entropy: A bit-based measure of how hard the password is to guess. Higher is stronger.
- Show / Hide: Use the button on the right to toggle the visibility of what you're typing.
When This Comes in Handy
- Checking that a password you're about to set on a new account is strong enough.
- Revisiting a short, reused password and turning it into something stronger.
- Getting a quick sense of how strong a password-manager-generated string is.
- Showing family or teammates what actually makes a password strong.
Tips for a Strong Password
- Making a password longer helps more than adding symbols to a short one.
- A passphrase of a few unrelated words is long, memorable and strong.
- Avoid predictable strings like "password", "123456", "qwerty", names or birthdays.
- Use a different password for each service and keep them in a password manager.