How is password strength measured?
This tool calculates entropy (randomness, measured in bits) based on your password's length and the character types it uses (lowercase, uppercase, digits, symbols). The higher the entropy, the longer a brute-force attack would take to guess it β and it grows exponentially, not linearly.
A long password often beats a short, "complex" one
An 8-character password with a couple of symbols crammed in is often less secure than a 20-plus character passphrase made of several unrelated words. Length increases entropy far more dramatically than adding a symbol or two.
Want to generate a strong password?
If you'd rather generate a secure random password from scratch, try our Password Generator.
Frequently Asked Questions
Is my password stored anywhere?
No. This tool runs entirely in your browser β nothing you type is sent to or stored on a server.
Do real attacks work exactly like this calculation?
No. Real attacks often combine dictionary attacks, leaked-password reuse, and other techniques, so this tool's number is a theoretical reference point assuming pure brute force, not a guarantee.