Passphrase
correct horse battery staple
Summary
Entropy bits and strength label from length and character pool
Encoding & Decoding
Passphrase Entropy Estimator — Search Space and Crack Time
Estimate Shannon entropy, search-space size, and theoretical crack time from passphrase length and character pool, with a strength label. Calculation stays in the browser. Labels are heuristic—high entropy does not prove a passphrase is safe against every attack.
EntropyPassphraseSecurity
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Passphrase Entropy Estimator
Estimate Shannon entropy, search-space size, and theoretical crack time from passphrase length and character pool, with a strength label. Calculation stays in the browser. Labels are heuristic—high entropy does not prove a passphrase is safe against every attack.
输入口令后自动估算
Evaluate Passphrase (输入测试密码 / 断句)
H
Shannon Entropy
0.0 bits
Weak
Character Pool Size (N)
Length (L) 0
Pool Size (N) 0
Space (N^L) 0
Crack Time (100B Guesses/s)
InstantUse cases
- Check whether a passphrase is long enough in entropy terms
- Compare entropy under different character pools
- Run a quick local strength rough-check before compliance reviews
How to use
- Enter a passphrase or short phrase
- Review entropy bits, search space, and estimated time
- Copy the summary if needed
Example input and output
FAQ
How is this different from the password strength tester?
Both estimate locally. This tool emphasizes entropy bits, search space, and time scale. The password strength tester adds a clearer score bar and improvement tips.
Does the passphrase leave the browser?
No. Entropy and time estimates are calculated locally.
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