Are passphrases more secure than passwords?

Passphrases can be very secure because length is a key factor in password strength. A 4-word passphrase has more entropy than most shorter complex passwords.

How many words should a passphrase have?

At least 4 completely random words for general use, 5-6 for high-security accounts. Avoid predictable phrases or song lyrics — true randomness is key.

What Is a Passphrase? And Is It Better Than a Password?

A passphrase is a password made of multiple random words strung together — like correct-horse-battery-staple. They've become increasingly popular because they're both easier to remember and often more secure than traditional character-based passwords.

What Is a Passphrase?

A passphrase is a sequence of random words used as a password. The concept was popularised by the XKCD comic "Password Strength" (2011) and formalised through Diceware — a method where physical dice rolls are used to select words from a list, ensuring true randomness.

The key word is random. A passphrase like "sunny-mountain-river" is not strong because those words relate to each other — a human might think of the same combination. A passphrase like "wagon-precise-atlas-eleven" is strong because the words were selected randomly from a large list.

Why Long Is More Secure Than Complex

Password security is measured in bits of entropy — the number of possible passwords an attacker must try. Each bit of entropy doubles the search space. A 4-word passphrase from the 7,776-word EFF list has 4 × log2(7776) ≈ 52 bits of entropy. A random 8-character password with uppercase, lowercase, digits and symbols has about 52 bits as well. So they're equivalent in security — but the passphrase is far easier to remember.

A 6-word passphrase has ~77 bits — stronger than a random 12-character password (~72 bits). This is why security experts increasingly recommend passphrases for anything you need to type or remember, particularly master passwords for password managers.

Passphrase vs Password: Head to Head

Memorability: Passphrases win clearly. "wagon-precise-atlas-eleven" is far easier to remember than "Xk9#mP2@qR5!". This means people are less likely to write them on sticky notes or reuse them.

Security per length: Roughly equivalent at 4 words vs 8 random characters. Passphrase wins as you add more words.

Typing ease: Passphrases are much easier to type on mobile or tablet. No fumbling with special characters.

Site compatibility: Some sites don't allow spaces or have short maximum password lengths. A random password generator may be more practical for these.

Brute-force resistance: Both are equally resistant if the entropy is equivalent. Passphrases are more resistant to dictionary attacks that target patterns in character-based passwords.

When to Use Each

Use a passphrase for: your password manager master password, full disk encryption (BitLocker, FileVault), sudo/admin account passwords, anything you need to remember and type regularly.

Use a random password for: anything stored in a password manager (since you don't need to remember it), accounts with length restrictions, cases where spaces aren't allowed.

Passphrase Rules That Actually Matter

First: the words must be random. Don't pick words that relate to you, your interests, or that you'd naturally think of. Use a proper generator like our passphrase generator which uses crypto.getRandomValues().

Second: use at least 4 words, preferably 5 or 6. Three words is too short for anything important.

Third: capitalising and adding a number helps satisfy site requirements without meaningfully reducing security if you apply them consistently (e.g., always capitalise first word, always append a number).

Passphrases Don't Replace 2FA

A strong passphrase protects you against password guessing — but not against phishing, data breaches where the server is compromised, or a keylogger on your device. Two-factor authentication provides a layer of protection even when your password is somehow obtained. Use a strong passphrase and enable 2FA on every account that supports it.

Passphrase vs Password: What Is the Difference?

A traditional password is typically a short, complex string of random characters — something like X7#mQ2!. A passphrase is a sequence of multiple ordinary words — something like correct-horse-battery-staple. The key insight is that length matters far more than character complexity for security. A 4-word passphrase of common words has more entropy (randomness) than most 8-character passwords because the sheer number of possible word combinations is astronomically large.

The famous XKCD comic "Password Strength" illustrated this perfectly: a password like Tr0ub4dor&3 looks complex but has only about 28 bits of entropy and is hard to remember. Four random words have about 44 bits of entropy and are far easier to recall. Entropy measures the unpredictability of a password — more bits means more possible combinations for an attacker to try.

How Secure Is a Passphrase Really?

The security of a passphrase depends on how randomly the words are chosen and how many words are used. Using four completely random words from a large wordlist gives you approximately 51 bits of entropy — enough to resist all but the most determined nation-state attackers. Adding a fifth word pushes this to around 64 bits, considered very strong by modern standards. The critical rule is that the words must be chosen randomly, not by a human. People naturally choose related words which dramatically reduces effective entropy.

Diceware is the gold standard method: roll physical dice to select words from a numbered wordlist, guaranteeing true randomness. Our Passphrase Generator tool uses your browser's cryptographically secure random number generator to achieve the same result digitally.

When Should You Use a Passphrase?

Passphrases are ideal for any secret you need to type or remember: your device login password, your password manager's master password, disk encryption passphrases, and Wi-Fi network passwords. The master password for your password manager is the perfect passphrase use case — you need to remember it, type it regularly, and it needs to be very strong.

Common Passphrase Mistakes to Avoid

Never choose words yourself — human-chosen words are predictable. Do not use famous quotes, song lyrics, or phrases from books, as these appear in attacker wordlists. Avoid using fewer than four words. Do not modify words with predictable substitutions like replacing letters with numbers. And never reuse the same passphrase across multiple accounts.

Frequently Asked Questions

Are passphrases accepted by most websites? Most modern websites accept passphrases since they are just long strings of characters. Some older systems have short maximum password lengths that may prevent very long passphrases — this is a security flaw in those systems, not a problem with passphrases.

Should I add numbers or symbols to my passphrase? Adding truly random words is more effective than appending a number. Adding !42 to the end adds very little entropy compared to adding another random word.

What wordlist should I use for Diceware? The EFF's Large Wordlist is widely recommended — it contains 7,776 common English words chosen to be easy to spell and remember, paired with 5-dice roll combinations.