Password Strength Checker
Check how strong your password is.
How to use Password Strength Checker
Enter Your Password
Click inside the password input field labeled 'Enter Password' and type the password you want to check. The field accepts up to 128 characters.
View Real-Time Strength Analysis
As you type, the strength meter bar updates instantly showing a color-coded indicator: Red (Weak), Orange (Fair), Yellow (Good), or Green (Strong). The strength percentage displays above the bar.
Review Detailed Feedback
Below the strength meter, read specific recommendations including character length requirements, uppercase/lowercase usage, numbers, special characters, and common pattern warnings.
Improve Your Password
Follow the highlighted suggestions to strengthen your password. Add uppercase letters, numbers, and special characters (@, #, $, %, etc.) to move toward a 'Strong' rating.
Copy and Save Your Password
Once satisfied with the strength level, click the 'Copy' button next to the input field to copy your password to clipboard, then save it in a secure password manager.
Related Tools
Password strength checker, test your password security instantly
Password strength checker, test your password security instantly
Want to know if your password is strong enough? Use ToolHQ's free password strength checker to test your password's security instantly. Your password is never sent to any server -- the check happens entirely in your browser.
ToolHQ's password strength checker is a free browser-based tool that analyzes your password in real time, showing a strength score, what makes the password weak or strong, and specific suggestions for improvement.
Most people use passwords that are far weaker than they think. This tool gives you an objective measure based on the same criteria that security standards bodies and password auditing software use.
Key Takeaways
- Your password is never sent to any server -- all analysis runs in your browser
- Scores passwords across multiple dimensions: length, character variety, patterns, and entropy
- Detects common patterns like dictionary words, keyboard walks (qwerty), and repeated characters
- Shows estimated time to crack under various attack methods
- Free with no login and no usage limits
What makes a password strong?
Password strength is not one thing -- it is the product of several factors working together. A password that passes one test can still be cracked quickly if it fails others.
According to NIST Special Publication 800-63B (the US federal standard for digital identity), the most important factor in password strength is length. NIST explicitly moved away from complex character-mixing rules (like "must include upper, lower, number, symbol") and toward longer, memorable passwords. Their guidance as of its latest revision recommends:
- Minimum 8 characters for standard passwords
- At least 15 characters for high-security accounts
- Allowing all printable ASCII characters and Unicode
- Checking passwords against lists of known compromised passwords rather than mandating character-class rules
The Wikipedia article on password strength defines strength in terms of entropy -- the measure of how unpredictable a password is. A truly random 12-character password drawn from a 95-character set (printable ASCII) has about 79 bits of entropy. A common word with predictable substitutions (like "P@ssw0rd") has far less entropy than its appearance suggests.
Key factors the checker evaluates:
- Length: Each additional character multiplies the number of possible passwords. A 16-character password is vastly harder to crack than an 8-character one of equal complexity.
- Character variety: Using uppercase, lowercase, numbers, and symbols increases the character set size, multiplying the search space.
- Predictable patterns: Dictionary words, names, dates, keyboard walks (qwerty, 12345), and repeated characters all reduce effective entropy even in longer passwords.
- Common passwords: The top 10,000 most-used passwords (like "password123" or "iloveyou") are checked and flagged immediately.
Why you need to test your password strength
Passwords that feel strong often are not -- and the gap between perceived and actual security can be dangerous.
Mini-story: Nikolai is a 45-year-old accountant who had been using the password "Summer2019!" for most of his accounts because it "had everything" -- uppercase, lowercase, number, and symbol. He typed it into ToolHQ's password strength checker and was surprised to see a "weak" rating. The checker showed that while it met character-class rules, it contained a dictionary word (Summer), a year (2019), and a common suffix pattern (!), reducing its real entropy to the equivalent of a much shorter random password. Nikolai replaced it with a 16-character random passphrase generated by a password manager. Time-to-crack went from hours to centuries.
Why password strength matters:
- Brute force attacks: Automated tools try billions of password combinations per second against leaked credential databases. Weak passwords are cracked in seconds.
- Credential stuffing: When one service is breached, attackers try those credentials against banks, email, and social accounts. Reused or weak passwords compound the risk.
- Phishing resilience: Strong, unique passwords limit damage when one account is compromised.
- Compliance requirements: Many organizations require passwords to meet minimum strength thresholds for regulatory compliance (PCI DSS, HIPAA, SOC 2).
Check your password strength at ToolHQ
How to use the password strength checker
- Open ToolHQ's password strength checker in your browser.
- Type your password into the input field. Your password is never sent anywhere -- analysis happens instantly in your browser.
- Review the strength score (typically shown as Weak, Fair, Good, Strong, or Very Strong) and the supporting details.
- Read the specific feedback. The checker tells you exactly why the password scored as it did -- too short, common word detected, no character variety, etc.
- Improve your password based on the feedback, or generate a strong one using ToolHQ's password generator.
What the strength levels mean
Weak: The password could be cracked in seconds to hours. It likely contains a dictionary word, is too short, follows a common pattern, or appears in breach databases. Do not use weak passwords for any account.
Fair: Passes basic checks but has identifiable weaknesses. May be acceptable for low-stakes accounts but should not be used for email, banking, or any account that stores sensitive data.
Good: Reasonably hard to crack with typical automated attacks. Suitable for most accounts but can be improved.
Strong: Resistant to brute force and dictionary attacks. Suitable for all accounts.
Very strong: Would take centuries to crack under current computing capabilities. This is the target for high-security accounts.
Mini-story: Yuki is a 31-year-old HR manager who was updating her company's password policy. She needed to demonstrate to employees why "easy to remember" passwords were insufficient. She used ToolHQ's password strength checker to test a series of passwords she expected employees might be using. "CompanyName2024!" scored Fair. "John@2024" scored Weak. "ToolHQAdmin" scored Weak. She showed these results during a security training session, then demonstrated that a random 16-character passphrase like "horse-battery-pine-7" scored Very Strong. The visual comparison helped employees understand the issue immediately.
For generating strong passwords, use ToolHQ's password generator. For creating secure hashes, try ToolHQ's hash generator. Browse all security tools in the ToolHQ security category.
Frequently asked questions
Is my password sent anywhere when I test it?
No. ToolHQ's password strength checker runs entirely in your browser. Your password is never sent to any server and never leaves your device. You can verify this by disconnecting from the internet -- the tool still works.
What is a good password length?
NIST SP 800-63B recommends at least 15 characters for high-value accounts. Length has the biggest impact on resistance to brute force attacks. A 16-character random password is exponentially stronger than an 8-character one, even with complex character mixing.
Should I use a passphrase instead of a complex password?
Yes, in many cases. A passphrase like "correct-horse-battery-staple" (from a famous XKCD comic) has high entropy because of length, even though it uses only lowercase letters and hyphens. ToolHQ's password generator can create both random character passwords and passphrases.
What is password entropy?
Entropy measures unpredictability in bits. Higher entropy means more possible combinations and therefore more resistance to guessing. A coin flip has 1 bit of entropy. A password drawn randomly from 95 characters has about 6.57 bits per character. A 12-character random password has about 79 bits -- astronomically more than a common dictionary word.
Should I check whether my password has been in a data breach?
Yes. Even a strong password is compromised if it has appeared in a known data breach. Have I Been Pwned (haveibeenpwned.com), operated by security researcher Troy Hunt, maintains a database of over 10 billion passwords from publicly known breaches. You can check any password there using a k-anonymity model: only the first 5 characters of your password's hash are sent to the server, so your actual password is never transmitted. Using HIBP alongside a strength checker covers both dimensions: a password should be both strong (high entropy) AND not previously exposed in a breach.
What makes "P@ssw0rd" weak despite having all character types?
Character substitutions like @ for a, 0 for o, and! at the end are so common that attackers add them to dictionary attack rules. Automated tools try all common substitutions, so "P@ssw0rd" provides little more protection than "Password" for practical attack scenarios.
The short version
A password that feels strong can still be cracked quickly if it follows predictable patterns, contains dictionary words, or is too short. ToolHQ's password strength checker evaluates your password against real security criteria -- entropy, length, patterns, and common password lists -- and tells you exactly how to improve it. Your password is never sent to any server.
Test your current passwords. Then make them better.
For creating strong passwords, use ToolHQ's password generator. For secure hashing, use ToolHQ's hash generator. Browse all security tools at the ToolHQ security category.