Password Strength Checker

Test password strength and get instant security feedback

UtilitiesFREEYour data never leaves your browser

100% freeNo signupRuns in your browser

Built by WOWHOW Team · 14+ yrs engineering

Password Strength Checker is a free, browser-based tool that lets you test password strength and get instant security feedback — with zero signup, zero installation. Your data never leaves your browser. Part of 138+ free developer and business tools at wowhow.cloud, built and maintained by a team with 14+ years of hands-on development experience.

TOOLPassword Strength Checker

Check Password Strength

Start typing to see real-time strength analysis

Password Generator

Length16

864

Uppercase (A-Z)Lowercase (a-z)Numbers (0-9)Symbols (!@#)

About Password Strength Checker

Password strength analysis goes beyond simple length and character-type checks. Sophisticated strength estimators model the patterns that attackers actually exploit: dictionary words, keyboard walks, common substitutions (@ for "a"), repeated characters, and sequential numbers. Understanding your password's estimated crack time against real-world attack benchmarks lets you make an informed decision about whether it is adequate protection for the account it guards.

How It Works

The checker calculates entropy based on the detected character pool: lowercase (26), uppercase (52), digits (62), symbols (95 printable ASCII characters). It then scans the password for common structural weaknesses — dictionary words, keyboard patterns, leet-speak substitutions, and repeated character runs — and applies a penalty to the entropy estimate for each weakness found.

Crack time is estimated for two threat models: online attacks (throttled at 100 attempts/second, representing a rate-limited login endpoint) and offline GPU attacks (10 billion attempts/second, representing a leaked hash cracked locally). Entropy is mapped to crack time as 2^entropy ÷ attack_speed.

The security checklist shows exactly which criteria pass or fail: minimum length, character variety, absence of common patterns, and absence of known-compromised passwords from common breach lists.

Who Is This For

A company IT administrator testing the strength of a proposed new employee password policy before rolling it out to 500 users.

A developer evaluating whether the password their users are likely to choose — based on observed patterns in other breach datasets — meets a minimum security bar for their application.

A student learning cybersecurity concepts who wants to see concretely why "P@ssw0rd" scores weak despite meeting typical complexity requirements.

A personal user auditing their existing passwords by checking each one to identify which accounts have dangerously weak credentials before switching to a password manager.

Scope note: This checker estimates strength based on structure and entropy — it does not query Have I Been Pwned or any breach database, so a password might score "strong" structurally while being present in a known breach list. For comprehensive checks, use a password manager that integrates breach database lookups.

How to Use

Type or paste your password in the input field

See real-time strength analysis and crack time estimates

Review the security checklist to understand weaknesses

Use the generator below to create a strong password

Copy the generated password with one click

Frequently Asked Questions

Absolutely not. All analysis runs entirely in your browser using JavaScript. Your password never leaves your device.

Length is the biggest factor. A 16+ character password with mixed characters is extremely difficult to crack. Avoid dictionary words and keyboard patterns.

Based on entropy (randomness) of your password and typical attack speeds. Online attacks: 100 tries/second. Offline GPU attacks: 100 billion tries/second.

Entropy measures password unpredictability in bits. 40+ bits is fair, 60+ is strong, 80+ is very strong.

Lowercase-only passwords draw from a pool of just 26 characters, giving 4.7 bits of entropy per character. A 12-character lowercase password has about 56 bits of entropy — crackable in hours with a GPU. Adding uppercase (52 characters), digits (62), and symbols (95) increases bits per character to 6.57, pushing the same 12 characters to 79 bits — a massively harder target.

The checker flags: sequential characters (abc, 123), keyboard patterns (qwerty, asdf), repeated characters (aaa, 111), dictionary words, common password structures (Capital + word + number + symbol like Password1!), and single-character substitutions (@ for a, 3 for e) that attackers know to try first.

Yes. Password managers (1Password, Bitwarden, Dashlane) let you use a unique, fully random 20-character password for every site without memorizing each one. You only memorize one strong master password. This is the single biggest security improvement most people can make — reusing passwords across sites is far more dangerous than using a slightly shorter unique password.