How to Check Password Strength and Improve Your Security

"Use a strong password" is good advice, but what does "strong" actually mean? A password strength checker quantifies it — measuring entropy in bits, estimating crack time against modern hardware, and identifying specific weaknesses like dictionary words or common patterns.

How password strength is measured

Password strength is measured in bits of entropy — the logarithm (base 2) of the number of possible combinations. A truly random 8-character password using mixed case, digits, and symbols has about 52 bits of entropy. The ToolStand Password Strength Checker calculates entropy based on character set size and length, then estimates how long it would take to crack using different hardware scenarios: a single GPU, a botnet, or a nation-state actor.

What makes passwords weak

Dictionary words. "password123" is in every cracking dictionary and takes milliseconds to break. Common substitutions. "p@ssw0rd" looks clever but cracking tools check these substitutions automatically — it is barely stronger than the original. Short length. A 6-character password, regardless of complexity, can be brute-forced in seconds. Personal information. Birthdays, pet names, and street addresses are guessable with minimal research.

Building better passwords

The checker provides improvement tips: add length (each additional character multiplies the search space by the character set size), use random characters rather than patterns, and avoid sequences on the keyboard. For generating strong passwords from scratch, use the Password Generator with configurable length and character sets.

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