All Tools

Password Strength Checker

Test password strength with entropy analysis, pattern detection, and crack-time estimates. Runs entirely in your browser.

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Privacy: the analysis runs locally in your browser. The password is never transmitted, logged, or stored.

Privacy and how this works

  • Runs entirely in your browser. Strength analysis and password generation run locally in JavaScript. Your password is never sent to, logged by, or stored on Vulnify servers.
  • Safe to test real candidates. Because nothing leaves your device, you can sanity-check passwords before saving them in a manager. Disconnect from the network after loading the page and it still works.
  • Estimates, not guarantees. Crack-time figures assume an offline attack against a fast hash. Use them to compare options, not as a promise of real-world safety.

Generate Strong Password

Create a random password locally, then analyze it or copy it into your password manager.

What This Tool Checks

  • Entropy and estimated crack time
  • Common password and dictionary-word detection
  • Sequences, repeats, keyboard walks, and embedded years

Why It Matters

Weak and reused passwords remain the most common initial access vector in real breaches. Length and unpredictability matter far more than complexity rules, and a realistic crack-time estimate makes that trade-off concrete.

Best For

Best for individuals and teams sanity-checking password candidates, writing password policy, or demonstrating why passphrases and managers beat short complex passwords.

What To Do Next

Use the analysis to replace weak passwords with long passphrases or generated secrets, store them in a password manager, and enable multi-factor authentication on important accounts.

Related Resources

Read The GuideRead The Fix PageSee Plans

Is my password sent to a server?

No. The analysis runs entirely in your browser with JavaScript. The password is never transmitted, logged, or stored, and the page works even if you disconnect from the network after loading it.

Why is my complex-looking password rated as weak?

Complexity that follows a predictable template, such as a capitalized word with a digit and an exclamation mark at the end, adds far less strength than it appears to. Cracking tools apply those exact patterns first. A longer passphrase of random words usually scores much higher.

How accurate is the crack-time estimate?

It is an order-of-magnitude estimate that assumes an offline attack against a fast hash at ten billion guesses per second, which is the conservative scenario where the attacker already stole the password hash. Use it to compare candidates rather than as a guarantee.