Passphrase Generator
GeneratorsEverything runs locally in your browser — nothing is uploaded
A 16-character random password is strong but hard to remember; a passphrase takes another route. Draw a few words from a list and join them: easy to say, easy to recall, and its strength depends entirely on how big the list is and how many words you draw. Six words from a 500-word list is about 54 bits, and adding a digit and a symbol pushes it higher. The entropy here is computed from the actual list size, not from how long the phrase looks — so switching to the 100-word short list makes the rating drop immediately: the same six words are about 40 bits. The tool also checks the result against a common-password list. Set a seed to reproduce the same passphrase. Everything runs in your browser.
Features
- 500 built-in 3–7 letter common words, plus a 100-word four-letter list
- Separator: hyphen, space, dot, underscore or none
- Optional random capitals, one inserted digit and one inserted symbol
- Entropy estimate (log2(list size) × words, plus any digit or symbol)
- Strength rating computed from the actual list size, never a hard-coded 500
- Checks the result against the common-password list
- A seed reproduces the exact same passphrase
How to use
- Choose the number of words and the word list
- Pick a separator, and turn on capitals, digits or symbols as needed
- Enter a seed to reproduce one, or leave it blank for true randomness
- The passphrase, entropy estimate and rating appear immediately
FAQ
- How strong are six words, exactly?
- It depends on the list. Six words from a 500-word list is log2(500) × 6, about 54 bits, and higher with a digit and symbol. The same six words from the 100-word short list are only about 40 bits — so looking long is not the same as being strong; the list size and word count are what matter.
- Why not just use a long random password?
- A long random password is stronger, but it is hard to remember, so people write it on a sticky note and the real strength drops. A passphrase trades a little entropy for memorability, a common security trade-off.
- Does a seed make it weaker?
- It makes the passphrase reproducible, but no longer cryptographically random: anyone who knows the seed can recompute it. For a password you will actually use, leave the seed blank.
- How much entropy do the digit and symbol add?
- A decimal digit adds log2(10) ≈ 3.3 bits, and a symbol adds log2(number of symbols). The insertion position carries a little entropy too, but it is negligible and is deliberately not counted.
- Is anything uploaded?
- No. It is all computed in memory in your browser, no request is made, and it works offline.
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