Password Strength Checker — How Strong Is Your Password?
Wondering if your password is strong enough to keep your accounts safe? This tool checks your password right in your browser and tells you how secure it is. It looks at how long your password is, whether it uses a mix of letters, numbers, and symbols, and whether it avoids common patterns that hackers try first. You get a strength rating and specific tips to improve it. Your password is never sent anywhere. Everything happens on your device only, so it is safe to test your real passwords here.
Frequently Asked Questions
What makes a password strong?
A strong password is at least 12 characters long and includes a mix of uppercase letters, lowercase letters, numbers, and symbols. Avoid dictionary words, your name, your birthdate, or common patterns like 123456 or qwerty.
Is my password saved when I use this tool?
No. This tool runs entirely in your browser. Your password is never sent to any server and is never stored anywhere. You can safely test real passwords here.
How long should a password be?
Security experts recommend at least 12 characters for most accounts. For banking, email, and other sensitive accounts, aim for 16 or more characters. Longer passwords are much harder to crack even if they only use letters.
Should I use a password manager?
Yes. A password manager lets you create a unique, strong password for every site without having to remember them all. This is the single most effective thing you can do to protect your online accounts.
What are the most common passwords hackers try first?
Hackers try passwords like "123456", "password", "qwerty", "abc123", and your name or birth year first. They also try words from the dictionary with simple substitutions like replacing "a" with "@". Avoid all of these patterns.
What is password entropy and why does it matter?
Password entropy measures how unpredictable a password is, expressed in bits. A password with 50 bits of entropy has 2^50 possible combinations. Each additional character or character type you add multiplies the combinations. A 12-character password using all four character types (uppercase, lowercase, numbers, symbols) has roughly 79 bits of entropy — far too many for a brute-force attack to crack in any reasonable time.
Is a long password better than a short complex one?
Generally yes. A 20-character lowercase-only passphrase is harder to crack than an 8-character password mixing all character types. Length has an exponential effect on the number of possible combinations. The best passwords are both long and use a variety of character types — a 16-character passphrase with a number and symbol added is extremely strong.
What is credential stuffing?
Credential stuffing is an attack where hackers take usernames and passwords leaked in one data breach and try them automatically on hundreds of other websites. If you reuse the same password across sites, one breach can compromise every account. A unique password per site is the only defense — use a password manager to make this practical.
How the Score Works
This tool checks 9 criteria: length (8+, 12+, 16+ characters), presence of lowercase letters, uppercase letters, numbers, and symbols, absence of repeating characters, and avoidance of common password patterns. Each criterion adds to the score, which maps to 5 strength tiers from Very Weak to Strong.
Password Entropy
Entropy measures unpredictability in bits. Adding symbols to an 8-character password raises the character pool from 62 to 94 options, increasing entropy by about 5 bits. Each extra character multiplies combinations exponentially — going from 8 to 12 characters has a larger impact than adding symbols to an 8-character password.
Common Attack Methods
Brute force tries every combination. Dictionary attacks try common words and variations. Credential stuffing uses leaked passwords from data breaches. Rule-based attacks try common substitutions (a→@, e→3). A strong, unique password defeats all of these because there is no shortcut — every combination must be tried.
When to Use This
Use before setting a new password for a sensitive account, when reviewing old passwords you may have created before learning better habits, when teaching others about password security, or whenever you want a quick sanity check before committing to a new password.
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