Analyze your password strength in real-time. Get crack time estimates, entropy calculation, and specific improvement suggestions. 100% private — nothing is stored or sent.
🔒 Password is checked locally in your browser — never stored or transmitted
The Logrith Password Strength Checker analyzes a password's length, character variety, and common patterns to estimate how resistant it would be to guessing and brute-force attacks — entirely within your browser, with nothing ever transmitted anywhere. It also estimates realistic crack times under different attack scenarios, giving a concrete sense of how long a given password would actually hold up.
Password strength isn't just about following a vague rule like "use a mix of letters and numbers." The actual security of a password comes down to how many possible combinations an attacker would need to try before guessing it correctly, and that number is shaped by both length and character variety — with length mattering considerably more than most people realize.
Entropy is calculated using the formula log2(character set size ^ password length), and it represents, in bits, how many guesses an attacker would theoretically need to try in the worst case. A password using only lowercase letters has a character set of 26, while one mixing uppercase, lowercase, digits, and symbols might have a character set closer to 90-95. Because entropy grows with the length exponent, a longer password with a smaller character set can still be stronger than a shorter password with a larger character set — which is part of why security experts increasingly recommend long passphrases over short, complex-looking passwords.
A common misconception is that adding symbols and numbers to a short password makes it strong. In reality, length has a much larger effect on total possible combinations than character variety does. An 8-character password, even with a full mix of character types, has fewer possible combinations than a 16-character password made of just lowercase letters. This is why many current security guidelines favor long, memorable passphrases — like a random string of several unrelated words — over short, symbol-heavy passwords that are both harder to remember and, counterintuitively, often weaker.
This tool estimates how long different types of attacks would realistically take to guess your password. An "online attack" scenario assumes an attacker is guessing through a live login form, which is typically rate-limited to around 1,000 attempts per second by the target service's security measures. An "offline fast hash" scenario assumes an attacker has somehow obtained a database of hashed passwords and is cracking them offline using powerful GPU hardware, capable of roughly 10 billion guesses per second for weaker hash algorithms like unsalted MD5. The difference between these two numbers is enormous, which is exactly why a password that feels "secure enough" against a login form could still be dangerously weak if the underlying password database were ever breached.
Your password is analyzed entirely within your browser using JavaScript — it is never transmitted to a server, logged, or stored anywhere, and disappears the moment you close or refresh the tab. This is an important distinction from some online password checkers that do send your input elsewhere; this tool is built specifically so that never happens.