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Tips for entropy estimates
Entropy assumes randomness — patterned passwords score too high.
Bits are a model; attackers also use breach lists and guessing.
Dictionary words drastically reduce real-world strength.
Compare candidates of similar length rather than chasing a number.
Use entropy with length and uniqueness, not alone.
Entropy is a search-space estimate
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This view estimates bits of entropy from length and alphabet size — how large the guess space would be if the password were uniformly random.
Human-chosen strings are weaker than the formula. Use the number to compare candidates, not as a lab-grade measurement.
Estimate password entropy
Enter the candidate
Paste the string whose entropy you want to compare — typically something you generated, not a reused login.
Read the bit estimate
More bits means a larger brute-force space, assuming no dictionary structure.
Compare alternatives
Try a longer phrase or extra character class and see which estimate moves more.
Password entropy FAQ
Is entropy the same as the strength meter?
Related but not identical. Entropy here is a formula on length and alphabet; the strength tool also looks at patterns.
How many bits is “enough”?
For random generated secrets, high double digits of bits is the usual goal. Dictionary words collapse that number in practice.
Does this check Have I Been Pwned?
No. Use the separate pwned-password check for leak lookup.