Password Strength & Complexity Checker
Local ProcessingEvaluate password complexity, character distribution, and theoretical search-space entropy without sending data to servers.
How It Works & Processing Standards
Evaluate password complexity, character distribution, and theoretical search-space entropy without sending data to servers.
Tool processing runs in your browser. If you create a calculator or conversion share link, its values are included in the URL. See the privacy policy for account, analytics and advertising data.
Current Limits
- Maximum input length: 2,000,000 characters
Shows in bits how large a space a password could come from. Each extra character adds log2 of the class count, so you can compare which rule helps more.
Entropy is an upper bound assuming random generation. Human choices such as "password" fall to dictionary attacks much faster.
What You Can Do
- Length and classes
- How long it is and which of lower, upper, digits and symbols it uses.
- Search-space entropy
- Bits computed as length × log2(character-set size).
How to Use Password Strength & Complexity Checker
- 1Enter a passwordType the password, or a similar sample.
- 2Read the resultSee length, classes and entropy.
Examples
Common Use Cases
- Comparing how strong company password rules really are
- Deciding how much longer a new password should be
Frequently Asked Questions (FAQ)
How many bits are enough?
For random passwords, around 60 bits resists online guessing; aim for 80 or more if leaked hashes could be attacked offline. Adding length is the easiest way.