Password Strength Checker — Free Online Password Strength Test & Meter
Free online password strength checker. Test your password's security, get crack time estimates, entropy score, and instant strength feedback. 100% offline.
To check password strength, type a password into the field; the tool instantly shows a strength rating, estimated crack time, entropy and any weaknesses found, such as a common password, keyboard pattern or year.
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Password Strength Checker — Free Online Password Strength Test & Meter. Free online password strength checker. Test your password's security, get crack time estimates, entropy score, and instant strength feedback. 100% offline.
Instantly test how strong your password is with our free online password strength checker .
Type any password and get an immediate security assessment: crack time estimate, entropy score, character set size, and a visual password strength meter showing Weak, Fair, Good, Strong or Very Strong.
The estimate is lowered when the password contains a common password, a common English word, look-alike substitutions (such as 0 for o), a keyboard pattern, repeated characters, a sequence, a year or a date, and every weakness found is listed.
Everything runs in your browser — your password is never sent to any server. Perfect for developers auditing registration flows, IT teams testing corporate password policies, or anyone wanting to improve their personal security.
Why run a password strength test? A password that looks complex can still be cracked in seconds if it follows a common pattern (like "Password123").
Our password strength test goes beyond just checking length — it models an attacker who tries common passwords and patterns before brute force, estimates the time needed at 1 billion guesses per second and lists the weaknesses it found.
The entropy estimate tells you roughly how much randomness your password has: higher entropy = harder to crack. The built-in lists are small (the most common passwords and 2,048 common English words), so treat a good result as an upper bound, not a guarantee.
Need a stronger password? Try our Passphrase Generator for memorable high-entropy credentials, or our Bcrypt Generator to hash passwords securely.
Frequently asked questions
How do I test my password strength?
Type or paste the password into the input box. The strength bar and label (Weak, Fair, Good, Strong or Very Strong) appear immediately, with the estimated time to crack it, a list of weaknesses found, the password length, entropy, character set size and a score out of 100.
How is the crack time calculated?
It starts from brute force, the length multiplied by log2 of the character set size, then finds the cheapest way to build the password from known patterns and single random characters, as an attacker who tries common passwords and patterns first would. The crack time assumes 1 billion guesses per second. For example, 12 random characters mixing all four character types give about 79 bits.
What is the character set size?
It is the number of possible characters implied by what you typed: 26 for lowercase letters, 26 for uppercase, 10 for digits and 32 for symbols, added together. A password that uses all four groups has a character set size of 94.
How is the strength rating decided?
The score is entropy divided by 128 bits, capped at 100. Below 20 is Weak, 20 to 39 Fair, 40 to 59 Good, 60 to 79 Strong and 80 or more Very Strong, so Very Strong needs about 102 bits of entropy or more.
Which weaknesses does the checker detect?
Common passwords from a built-in list of about 190, common English words from a 2,048-word list, look-alike substitutions such as 0 for o or 3 for e, keyboard patterns such as qwerty or 1qaz2wsx, repeated characters or blocks, sequences such as abcd or 13579, years from 1900 to 2099 and dates. Names and leaked passwords outside these lists are not recognised, so the result is an upper bound.
Is my password sent anywhere?
No. The analysis runs in your browser with built-in lists, the input is a masked password field, and nothing is uploaded or stored.
How to use this online tool
Password Strength Checker — Free Online Password Strength Test & Meter is designed for fast browser workflows when you need to format, validate, convert, decode, encode, generate, or inspect data without opening a heavy desktop app. Start with the input field or visible options, review the result, then copy or download the output for the next step.
Private processing in your browser
Password Strength Checker — Free Online Password Strength Test & Meter keeps the normal processing step local in your browser. That is useful for code snippets, tokens, documents, configuration values, text samples, and other material that should not be sent to a remote service unless you explicitly choose to share it.
When this tool is useful
Use Password Strength Checker — Free Online Password Strength Test & Meter for repeatable developer tasks, technical documentation, QA checks, quick conversions, debugging, content cleanup, and internal team workflows. The page focuses on clear inputs, immediate feedback, and output that is easy to reuse in code, reports, tickets, emails, or notes.
Practical tips
Before copying the final result, check important details such as spacing, casing, filenames, encoding, token structure, line breaks, or output format. Small checks prevent mistakes when the result is reused in source code, API requests, documentation, spreadsheets, or shared files.