Password Strength Checker FAQ

A Password Strength Checker is a security tool that helps you evaluate the security of your password. It assesses password strength by analyzing several factors:

• Password length
• Character diversity (uppercase, lowercase, numbers, symbols)
• Password entropy (complexity and unpredictability)
• Common password patterns or dictionary words

Based on these metrics, the tool estimates the time required to crack the password through brute force and provides suggestions for improvement, helping you create more secure passwords to prevent account breaches.

The tool is designed to keep structural analysis local and make breach checks optional. That means strength scoring, pattern detection, entropy estimates, and the deep report all run in your browser before any optional network lookup is involved.

Security and Privacy Features:

• Local structure analysis: The default analysis flow does not send your raw password to a server.
• No password storage: The page does not log or save the passwords you type.
• Optional breach check: The HIBP exposure lookup runs only when you click the breach-check button.
• Privacy-preserving query model: The optional breach check sends only a small hash prefix, not your raw password.

No web tool can promise absolute risk-free use, but this design keeps the default flow local and treats network lookups as an explicit, separate action.

A strong password typically has the following characteristics:

• Sufficient Length: 12 characters is good, but 16 or more is highly recommended.
• High Randomness: Avoid using birthdays, names, common words, or predictable sequences.
• Avoid predictable structure: Length matters, but avoiding names, dates, keyboard paths, and decorated dictionary words matters just as much.
• Uniqueness: Never reuse the same password across different websites or services.

Using our online password security assessment tool can quickly provide a password strength rating and an estimated crack time.

A low password strength score may be due to the following reasons:

• Too short - Passwords with fewer than 12 characters are generally weaker
• Single character type - Using only letters or numbers
• Uses common patterns - "123456", "qwerty", etc.
• Contains personal information - Name, birthday, phone number, etc.
• Repeated characters - "aaaa" or "1111"

The current checker tries to point out the main weakness category instead of only telling you to add symbols:

Password entropy is a mathematical measure of a password's complexity and unpredictability. It is calculated based on:

• The size of the character set used (e.g., lowercase letters = 26, all types = 70+)
• The length of the password
• The randomness of the characters

Higher entropy means the password is harder to guess or brute-force. The formula is:

Entropy = log₂(character_set_size^{password_length})

For example:

• 8-digit numeric password: log₂(10⁸) ≈ 26.5 bits of entropy
• 12-character mixed-case password: log₂(70¹²) ≈ 78 bits of entropy

Our tool calculates password entropy in real-time and provides a comprehensive assessment along with crack time.

Because those two numbers answer different questions, we show both instead of collapsing everything into a single score.

The assessment process has multiple stages:

• 1. Pattern detection: Local analysis looks for dictionary words, dates, keyboard paths, repeated chunks, and other common structures.
• 2. Entropy estimate: The tool also estimates theoretical randomness and brute-force difficulty.
• 3. Combined score: Structure risk and theoretical randomness are considered together so obviously guessable passwords do not look strong just because they are long.
• 4. Optional breach check: If you choose to run it, the page adds a separate historical exposure signal from public breach data.

In practice: entropy is closer to theoretical randomness, while the strength score is closer to real-world guessability. Reading both together is usually more useful than trusting either number on its own.

Because long and busy-looking passwords can still be predictable. Common reasons include:

• Predictable patterns: Common words, years, dates, names, keyboard paths, and decorated dictionary words are still modeled quickly by attackers.
• Low-quality length: Adding repeated chunks or a familiar suffix does not improve security as much as adding genuine randomness or unrelated words.
• Breach exposure: If you manually run the optional breach check and it finds a match, the password should be replaced even if its structure looks decent.

The deep-analysis report is there to show the main issue, the likely strategy type, and whether the better fix is a longer passphrase or a truly random password.

Yes, with excellent support. We have upgraded our core detection engine to the modern @zxcvbn-ts/core, which includes a dedicated Chinese dictionary and language model.

Features for checking Chinese passwords:

• Supports evaluation of all-Chinese character passwords.
• Accurately analyzes the security of mixed Chinese, English, numeric, and symbol passwords.
• Recognizes common patterns like Pinyin combinations.
• Scientifically calculates the entropy contribution of Chinese characters.

Example:

Whether you use a pure Chinese password or a mixed one, our tool can accurately assess its security.

The results are useful, but they should be treated as guidance rather than an absolute guarantee.

• Layered analysis: The tool combines pattern detection, entropy estimates, remediation logic, and optional breach information.
• Clear state handling: It distinguishes between not checked, checking, not found, compromised, and error rather than pretending every result is equally certain.
• Explicit limits: “Not found” does not mean perfectly safe, and crack-time estimates are still model-based approximations.

Crack-time values are best used for comparison between passwords, not as a promise about how long a real attack would take. For important accounts, a unique password plus MFA is still the safer standard.

No. Gongjupal provides a completely free online password checking service:

• No account registration required
• No software download needed
• No browser extension to install
• No usage limits

Just open the Password Strength Checker webpage to use it. It's fast and secure, supporting all modern browsers including Chrome, Firefox, Safari, and Edge.

The page does not store the passwords you type, and the default analysis flow does not send them to a server.

• Strength scoring, pattern detection, and the deep report run locally by default
• The page does not log the passwords you enter
• The breach check is optional and manually triggered
• The optional breach check uses a privacy-preserving query format instead of sending the raw password

If you do not want any network interaction at all, you can simply use the local analysis features and skip the breach-check button.

In addition to using strong passwords, we recommend the following security practices:

By combining these measures, you can significantly enhance your account security and effectively defend against various cyberattacks.