Password Strength Checker
Find out how strong a password is and get tips on what to improve. The assessment happens only in your browser.
Start typing to see the assessment.
The password is assessed only in your browser and is never sent, stored or logged anywhere.
How it works
You type a password and the tool assesses its strength, rating it from Weak to Very strong. The assessment considers two main factors: the length and the variety of character types (lowercase, uppercase, numbers and symbols).
Based on that, it estimates the password's "entropy", measured in bits — the higher it is, the more unpredictable and the harder to crack. The longer and more varied the password, the higher the entropy and the stronger the rating.
Beyond the score, the tool points out what's missing to improve: increase the length, add symbols, avoid repeated sequences. It's practical feedback, not just a verdict. Importantly, the password is analyzed entirely in your browser and is never sent, saved or logged anywhere.
When to use
Use it when you create a password and want to check that it holds up well before adopting it, or to assess old passwords you still use and suspect are weak. It's a good habit to check the passwords of your most important accounts — email, banking, social media.
It also works as a learning tool: by testing variations, you see in practice what really increases security. It's often surprising to realize that increasing length matters more than swapping a few letters for symbols. Understanding that helps you create better passwords from then on.
Practical examples
From weak to strong
The password "john2024" shows up as weak: short and predictable. A long, varied sequence with uppercase, lowercase, numbers and symbols reaches the strong or very strong rating, with much higher entropy.
The weight of length
Comparing two passwords shows the effect of size: adding more characters, even simple ones, usually raises the strength more than swapping a few letters for symbols in a short password. Length is the factor that counts most.
Common mistakes
The most common mistake is relying on obvious substitutions, like swapping "a" for "@" or "o" for "0". These tricks are very well known and barely increase the security of a word that already exists in the dictionary. The tool may even give a better score for the variety, but in practice those patterns are predictable.
Another mistake is thinking a strong password can be reused freely. Strength doesn't protect against leaks: if a site where you use that password is breached, it needs to be changed everywhere. The ideal is a different password per service.
It's also worth not confusing "hard to remember" with "strong". A password can be hard for you and still predictable to an attack if it's based on personal data or common patterns. Randomness and length are worth more than apparent complexity.
Frequently asked questions
Is my password sent to a server?
No. The assessment happens entirely in your browser. The password you type is never sent, stored or logged anywhere, so the test is safe.
What is password entropy?
It's a measure of unpredictability, in bits. The higher the entropy, the more possible combinations the password has and the harder it is to crack by trial and error. Length and variety increase entropy.
What makes a password stronger: length or symbols?
Both help, but length usually matters more. Adding characters greatly increases the possible combinations. The ideal is to combine generous length with a variety of types.
Is a password rated strong unbreakable?
No password is completely unbreakable, but a strong one makes an attack impractical. Combine it with unique passwords per service and, where possible, two-factor authentication.