Diceware Passphrase Generator
Generate 1–20 random words from EFF’s 7,776-word list and inspect the word count and estimated random bits.
About this diceware passphrase generator
Generate 1–20 random words from EFF’s 7,776-word list and inspect the word count and estimated random bits.
How this tool works
Selects each word independently from the 7,776-entry EFF large wordlist using crypto.getRandomValues. Rejection sampling removes modulo bias; words are joined with hyphens. Estimated random bits = n × log2(7776), rounded to one decimal.
- Enter 6 in “Input”.
- Click “Run locally”.
- In “Output”, check wordCount = 6, wordlistSize = 7776 and estimatedRandomBits = 77.5; the words may vary between runs.
Worked example
Scenario: Generate a six-word passphrase and inspect its word count and random-bit estimate.
Sample input:
Processing: Selects each word independently from the 7,776-entry EFF large wordlist using crypto.getRandomValues. Rejection sampling removes modulo bias; words are joined with hyphens. Estimated random bits = n × log2(7776), rounded to one decimal. In “Output”, check wordCount = 6, wordlistSize = 7776 and estimatedRandomBits = 77.5; the words may vary between runs.
Illustrative output:
Limits and verification
Enter a whole word count from 1 to 20 using ASCII digits; blank input defaults to 6. Fractions, signs, leading zeros and other formats are rejected. The browser must provide a cryptographic random source. Repeated words are allowed. Some EFF words contain a hyphen, so use the words array to identify word boundaries. The bit estimate assumes independent uniform selections; it is not a guarantee against attacks or device compromise.
Examples demonstrate an expected workflow; they do not prove every input or every branch of an external specification. Check important results with an independent source before using them for money, security, compliance, safety, or irreversible file changes.
Browser processing boundary
Tool input is processed by code running in the browser and is not intentionally sent to a CZOA processing API. The page can still request ordinary site assets, analytics, or advertising when those services are enabled. Browser extensions and managed-device software remain outside this tool's control.
Relevant references
These references govern or help explain the format, protocol, or calculation used here. Listing a reference does not claim certification or complete implementation of every optional feature.
- EFF Large Wordlist: 7776 entries
- Web Cryptography API: Crypto.getRandomValues
- Shannon entropy of independent uniform selections: n × log2(7776)
Content owner: CZOA Tools · Last reviewed: 2026-09-15 · Review methodology
How to use it
- Enter 6 in “Input”.
- Click “Run locally”.
- In “Output”, check wordCount = 6, wordlistSize = 7776 and estimatedRandomBits = 77.5; the words may vary between runs.
Frequently asked questions
What input range does Diceware Generator accept?+
It accepts a whole-word count from 1 through 20. Empty input uses six words; an invalid count raises an input error instead of silently changing the request.
How are the selected words represented?+
The result JSON contains the requested wordCount, an EFF large-list words array, and a passphrase made by joining exactly those random words with hyphens.
What did the browser fixture prove?+
With input 2 it returned two EFF-list words, a hyphen-joined matching passphrase, and a positive entropy estimate. The actual words are intentionally unpredictable.
Does estimated random bits guarantee a safe password?+
No. The estimate only derives from list size and word count. Safe use also depends on storing the passphrase, avoiding reuse, and the surrounding authentication system.