Calculate password entropy in bits to measure password strength against brute-force attacks. Code never leaves your device — formatting and validation run locally in your browser.
Content reviewed October 2026 · About Toolzum
Provides an interactive environment where users can write a regular expression pattern, test it against sample strings, and view real-time match. Code never leaves your device — formatting and validation run locally in your browser.
Estimate password crack times from length, charset, and attacker speed — entropy made visceral. Show why 8-char passwords fall in hours — local math, free, no signup.
Generate password hashes using PBKDF2-SHA256 with 600,000 iterations for secure password storage. Code never leaves your device — formatting and validation run locally in your browser.
Evaluates password strength using zxcvbn entropy analysis: 0–4 score, crack-time estimate, warnings, and fix suggestions.
Score your resume against a job description for ATS compatibility — keyword gaps, formatting flags, and fix suggestions. Applicants lift a 52/100 resume past 80 before applying — 1 credit per check, sign in free.
Entropy measures password randomness in bits. Higher entropy = harder to crack. It accounts for password length and character set size. 40 bits is weak, 60 bits is moderate, 80+ bits is strong.
Entropy = log2(character_pool_size ^ password_length). For example, an 8-character password using lowercase + uppercase + digits + symbols (94 chars) has log2(94^8) = 52.6 bits of entropy.
This tool shows entropy bits, strength, and score only — it does not estimate crack times. For time-to-crack math at attacker guess rates, use the Brute Force Time Estimator.
Balance entropy with memorability. A 16-character passphrase with moderate entropy (Diceware-style) is often more practical than a short high-entropy random string. Use a password manager for truly random passwords.
No. All calculations run locally in your browser. No password or entropy data is sent to any server.
Brute Force Time Estimator
Estimate password crack times from length, charset, and attacker speed — entropy made visceral. Show why 8-char passwords fall in hours — local math, free, no signup.
Two-Factor Auth Generator
Generate TOTP URIs for two-factor authentication setup with authenticator apps. Code never leaves your device — formatting and validation run locally in your browser.