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Password Strength Tester & Checker

Check how strong your password really is — live entropy analysis, crack-time estimates and instant fixes.

100% free No sign-up Private · runs in your browser

How to use the free online password strength tester

Type or paste a password to test.
Read the live strength meter and crack-time estimate.
Review what makes it strong or weak.
Generate a strong replacement with one click.

About this tool

Check how strong your password really is with a live analysis of length, character variety, entropy and the estimated time to crack it by brute force. Get instant, specific advice on how to harden weak passwords — and one-click access to a strong replacement. Everything is analyzed locally in your browser; your password is never uploaded or stored.

Key features

Live strength meter
Entropy & crack-time estimate
Character analysis
One-click strong replacement

Privacy first: every calculation and generation runs 100% locally in your web browser using the Web Crypto API. Your input never touches a server — nothing is stored, logged or sold.

Read the guide

Security · 5 min read

How password strength is really measured

Entropy, crack time and why 'Password1!' is weaker than you think.

Frequently asked questions

We combine length, character variety and entropy (bits of uncertainty). A 16-character password with mixed classes scores far higher than an 8-character one, even with symbols.

Never. The analysis runs entirely in your browser. Nothing you type is transmitted, logged or stored — close the tab and it's gone.

Aim for 'Strong' or higher: at least 12–16 characters, mixing cases, digits and symbols, and never a dictionary word or personal detail.

It estimates how long an offline brute-force attack would take with current hardware. Over trillions of years means the password is effectively uncrackable.