Random Passphrase Generator – Diceware-Style Passwords You Can Remember
A passphrase strings together several random dictionary words instead of a jumble of unrelated characters. The approach — popularized as Diceware and by the famous “correct horse battery staple” comic — trades a short, hard-to-remember password for a longer one built from words your brain already knows how to store. This tool generates passphrases like Correct-Horse-Battery-Staple-42! entirely in your browser, using the Web Crypto API so nothing you generate is ever sent to a server.
Why word-based passphrases work
Password strength comes down to entropy— how many guesses an attacker needs, on average, before finding the right answer. Each word drawn from this tool's roughly 690-word list contributes about log2(690) ≈ 9.4 bits of entropy. Five words already reach around 47 bits, and six words push past 56 bits — comparable to a fully random 9–10 character password, but far easier to type, remember, and read aloud. Adding numbers, a symbol, or randomized capitalization increases the entropy further without adding more words to memorize.
How the generator works
Each word is selected independently and uniformly at random from the wordlist using rejection sampling against crypto.getRandomValues, which avoids the subtle bias that naive Math.random()-based approaches introduce. You control the number of words, the separator between them, capitalization style (none, first word, Title Case, camelCase, random per word, or UPPERCASE), and whether to append random digits and a symbol. A live entropy counter and strength badge update instantly as you change any setting, so you can see the effect before generating anything.
Filtering the wordlist
Two optional filters trade a little entropy for practicality. Avoid Ambiguous / Hard-to-Spell Words removes entries with silent letters or unusual spelling patterns (like knight or dolphin) that are easy to mistype. Exclude Similar-Sounding Words removes homophones (like peak, which sounds like “peek” or “pique”) — useful if you'll ever read the passphrase aloud over the phone. You can also restrict word length with the Min / Max Word Length fields. The tool always keeps at least 100 usable words after filtering, since a smaller pool quietly weakens every passphrase drawn from it.
Targeting a specific entropy level
Rather than guessing how many words you need, set a Minimum Entropy Target in bits and the tool calculates the smallest word count that reaches it, given your current wordlist, capitalization, and number/symbol settings. This is useful when a security policy specifies a target strength (for example, 60 bits for a general account or 80+ bits for a master password or encryption key mnemonic) rather than a word count.
Reading the crack-time estimate
Below each result, the tool converts entropy into rough real-world crack times under three common attacker assumptions: a throttled online login (100 guesses/second), an offline slow hash like bcrypt (10,000 guesses/second), and an offline GPU cluster against a fast hash (10 billion guesses/second). These are estimates, not guarantees — actual attacker speed depends heavily on the system storing the passphrase — but they give a useful sense of scale beyond a raw bit count.
Common uses
Passphrases generated here work well as master passwords for a password manager, Wi-Fi network keys, encryption or wallet recovery mnemonics, and account passwords you need to type on a phone keyboard or communicate verbally to a colleague. Use the Number of Passphrases field to generate a batch at once — handy for onboarding several accounts or picking a favorite from a shortlist — then copy, download as TXT/CSV, or share the results directly from the results panel.