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Password Strength Checker

Analyze password entropy, check security rules, and estimate crack time at different attack speeds.

Enter a password to analyze

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Length

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Entropy (bits)

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Charset Size

Security Rules

○At least 8 characters

○At least 12 characters (recommended)

○Contains uppercase letters (A–Z)

○Contains lowercase letters (a–z)

○Contains numbers (0–9)

○Contains symbols (!@#$%...)

○No common patterns (123, abc, qwerty)

○No repeated characters (aaa, 111)

⏱ Estimated Crack Time

Online attack (100/sec)—

Offline MD5 (10B/sec)—

Offline SHA-256 (1B/sec)—

Bcrypt cost=10 (50/sec)—

Generate a Strong Password

About Password Strength Checker

Password Strength Checker is a free browser-based security tool that lets you analyze password entropy, check security rules, and estimate crack time at different attack speeds without sending sensitive data over the network. Cybersecurity professionals, developers, and privacy-conscious users trust client-side tools like this because your data never leaves your device. All cryptographic operations use your browser's built-in Web Crypto API for maximum security.

How to Use

Enter your data Paste or type your sensitive data into the input field. Remember: nothing leaves your browser.

Configure options Select the algorithm, encoding format, key size, or other parameters as needed.

Process Click the action button to encrypt, hash, encode, or perform the security operation.

Copy the output Copy the result securely. For sensitive outputs, make sure to store them in a safe location.

🔒 Privacy note: All processing happens locally in your browser. Your data is never sent to any server.

Why Use Password Strength Checker?

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True Client-Side Security All cryptographic operations run in your browser using the Web Crypto API. Your sensitive data — passwords, keys, encrypted messages — never touches any server.

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Industry-Standard Algorithms Password Strength Checker uses the same cryptographic algorithms trusted by banks, governments, and security professionals worldwide. No homebrew crypto.

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Open & Transparent View the source code right in your browser (Ctrl+U). Verify exactly what the tool does with your data — no hidden behavior, no tracking.

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No Registration Required Security tools should be accessible without creating accounts or sharing personal information. Use Password Strength Checker immediately — no sign-up, no email, no strings attached.

Frequently Asked Questions

Entropy measures unpredictability in bits. It's calculated as: log₂(charset_size^length). A password with 80+ bits of entropy is considered very strong. Each added character multiplies the combinations by the charset size.

No. All analysis is performed locally in your browser using pure JavaScript. Your password is never transmitted, logged, or stored. The page works completely offline after loading.

Length is the most important factor — each extra character exponentially increases combinations. Use 12+ characters with a mix of uppercase, lowercase, numbers, and symbols. Avoid dictionary words, names, dates, and keyboard patterns like "qwerty123".