Test your password strength in real-time. See entropy, estimated crack time, character analysis, and get actionable tips to make your passwords stronger. No data is stored or transmitted — everything runs in your browser.
Our checker evaluates passwords using multiple factors, not just length. Entropy is the primary measure — it represents the number of bits of randomness in your password. A password with 80+ bits of entropy is considered strong against modern attacks.
Character pool size is determined by which character types are present (lowercase = 26, uppercase = 26, digits = 10, symbols = 33). More types = larger pool = more entropy per character. Length is the most important factor — each additional character multiplies the total combinations exponentially.
We also detect common patterns that reduce effective strength: dictionary words, keyboard sequences (qwerty, 123456), repeated characters, and known compromised passwords. These reduce the entropy score because attackers check them first.
Our crack time estimate assumes an attacker performing 10 billion guesses per second — representative of a well-funded attacker using GPU clusters. A password with 40 bits of entropy would fall in about 2 minutes. A password with 60 bits would take 36 years. At 80 bits, we're talking about 38 million years.
These are brute-force estimates. If your password contains common words or patterns, it could be cracked much faster using dictionary attacks, which is why our tool penalises common patterns.
Length over complexity. A 20-character password using only lowercase letters has more entropy (94 bits) than a 10-character password using all character types (65 bits). Make it long first, complex second.
Randomness over memorability. Human-chosen passwords follow predictable patterns. Use a password generator for truly random passwords, and store them in a password manager.
Uniqueness per account. Even the strongest password becomes weak if you reuse it. A single data breach exposes that password across all your accounts.
Yes. This tool runs 100% in your browser. No passwords are transmitted to any server, stored in any database, or logged anywhere. All analysis happens entirely client-side using JavaScript. You can verify by disconnecting from the internet — the tool works perfectly offline.