Password vs Passphrase: Which Is More Secure?
A detailed comparison of random passwords and passphrases: security, usability, and when to use each.
What Is a Random Password?
A random password is a string of characters generated using a cryptographically secure random number generator. It draws from uppercase letters, lowercase letters, digits, and symbols: 88 characters in this tool (some rarely-used symbols like quotes and backslashes are excluded for compatibility).
~103 bits
Entropy (16 chars, full set)
16 chars
Typical length
What Is a Passphrase?
A passphrase is a sequence of randomly chosen words from a curated wordlist. The EFF Short Wordlist uses 1,296 common words (64 possibilities). Security comes from the number of words, not their complexity.
~45 bits
Entropy (4 words, capitalized)
~24 chars
Typical length
Security Comparison
| Factor | Random Password | Passphrase |
|---|---|---|
| Entropy per char | ~6.5 bits | ~1.9 bits (per char) |
| 16-char entropy | ~103 bits | ~45 bits (4 words) |
| Brute-force resistance | Excellent | Good (5+ words = excellent) |
| Dictionary attack | Immune | Resistant (random word choice) |
| Memorability | Very hard | Moderate |
| Typing speed | Slow (symbols) | Fast (common words) |
| Compatibility | Universal | Some length limits |
When to Use Each
Use a Random Password When...
Use a Passphrase When...
Crack Time Comparison
Assuming 10 billion guesses per second (a powerful GPU cluster):
8-char password (mixed)
52 bits entropy
3-word passphrase
34 bits entropy
12-char password (mixed)
78 bits entropy
4-word passphrase
45 bits entropy
16-char password (mixed)
103 bits entropy
6-word passphrase
68 bits entropy