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Diceware Passphrase Generator

Inspired by Arnold Reinhold's Diceware protocol and XKCD #936: combine truly random dictionary words into unbreakable passphrases that you can actually visualize and remember.

Zero Data Transmission Guarantee100% Client-Side

All computations run strictly inside your browser's local sandbox memory using the Web Cryptography API. We never store, log, or transmit your passwords.

Works Offline
Local CSPRNG
No Server Storage

Diceware Passphrase Generator

Memorable, high-entropy word combinations (XKCD-style)
~49 Bits Entropy
Generating...
4 dictionary wordsOffline GPU crack: 47 minutes
Entropy:49 bits
3 (Basic)4 (Recommended)5 (High Security)6 (Paranoid)8 (Maximum)
Capitalization Mode
Include Number
Include Special Symbol

Appends a random symbol (!@#$%&*?) to fulfill strict legacy password complexity policies.

Adds ~3 bits entropy
Why passphrases beat complex passwords:

Based on the legendary XKCD #936 principle: Four random common words like correct horse battery staple contain over 50-60 bits of mathematical entropy. They are exponentially harder for computers to brute-force than short scrambled strings like Tr0ub4dor&3, while remaining effortless for human memory.

The Science of Human-Memorable Entropy

For decades, security policies forced employees to construct passwords like P@$$w0rd99!. These strings are difficult for human brains to remember (leading people to scribble them on sticky notes under keyboards), yet trivially easy for modern cracking tools equipped with rule-based leetspeak mutations.

A passphrase shifts the security equation. Instead of scrambling characters, you select words uniformly at random from a large dictionary:

Diceware Formula: Entropy = N × log₂(Wordlist Size)
4 Words from ~1,200 list ≈ 42-45 bits | 5 Words ≈ 55-60 bits | 6 Words ≈ 70+ bits
MethodExampleEntropyHuman MemoryOffline Crack Time (100B/s)
Short "Complex"J#8k!2~35 bitsPoor< 1 second
Typical LeetspeakS@fe2025!~30-40 bits (rules)ModerateMinutes (Rule attack)
4-Word PassphraseCedar-Lagoon-Falcon-Stone~45-52 bitsHigh (Visual)Years
5-Word PassphraseSummit-Willow-Beacon-Jasper-Wave~60-70 bitsVery HighCenturies