Why is a passphrase stronger than a password?

A passphrase of several random words is both easier to remember and harder to crack than a short complex password, because its entropy grows with each word added rather than relying on a few hard-to-recall symbols.

How much entropy do the passphrases have?

The word list holds 260 words, so each word adds about 8 bits of entropy (log2 of 260). Five words give roughly 40 bits, six words about 48 bits, and adding a number or symbol adds a few bits more.

Are the words chosen securely?

Yes. Words are selected with the browser's crypto.getRandomValues secure random generator using rejection sampling to avoid modulo bias — not the predictable Math.random.

What is rejection sampling and why does it matter?

Naively taking a random number modulo the list size slightly favours some words. Rejection sampling discards values in the biased tail and redraws, so every word is exactly equally likely — important for honest entropy.

How many words should I use?

For most accounts four to five words are plenty; for a password-manager master password or disk encryption, use six or more. More words always means more entropy and a harder target.

Is my passphrase sent anywhere?

No. Generation happens entirely in your browser. Nothing is uploaded, logged or stored, so close the tab and it is gone.

Strong Passphrase Generator

A long passphrase made of random words is the modern recommendation for master passwords and any account you must remember: easy for you, hard for anyone else to guess. This generator picks words with your browser’s secure random source and shows a conservative entropy estimate so you can judge strength at a glance.

How it works

Words are drawn from a 260-word readable list using crypto.getRandomValues with rejection sampling, which discards biased draws so every word is exactly equally likely. The entropy estimate is built up additively:

Each word adds log2(260) ≈ 8.02 bits.
Adding a random number contributes log2(100) ≈ 6.6 bits.
Adding a symbol contributes log2 of the symbol-set size.

So entropy scales linearly with your chosen word count — more words, more bits, exponentially more guessing effort for an attacker.

Example

A 5-word passphrase such as:

brave-cedar-flint-meadow-tunic

has about 5 × 8.02 ≈ 40 bits of entropy. Bump it to six words for roughly 48 bits, or append a number/symbol for strict sites.

Words	Approx. entropy
4	~32 bits
5	~40 bits
6	~48 bits
7	~56 bits

Everything runs locally in your browser — nothing is ever uploaded.