Passphrase generator

Make a passphrase of random words with one click. It is made in your browser and is never sent or stored. Pick the language and the number of words and see how long it would take to guess.

Your passphrase

The passphrase is made in your browser and is never sent or stored. Only your settings (language of the words, number of words, separator) stay in this browser.

Strength

78 bits

Good

Bits of entropy: the passphrase was drawn at random from 2 to that power possibilities, and every extra bit doubles the guesses an attacker needs. This holds only for a passphrase made by this generator, not for one you thought up.

Time to guess it

Online login10 guesses a second (example): over 1 billion years
Stolen database, slow hashbcrypt, one RTX 5090: over 1 billion years
Stolen database, fast hashMD5, one RTX 5090: 16,000 years

The average time to find the password by trying possibilities one after another (on average half of them). The speeds are published benchmarks of one graphics card, see the method and sources below; an attacker may have many cards.

An estimate for information only, not financial, tax or technical advice. How it is calculated and where the data come from

How a passphrase works

A passphrase is several words drawn at random, for example from a list of a couple of thousand. Its strength comes from the number of words and the size of the list, not from odd characters: every word multiplies the number of possibilities by the size of the list.

It suits what you have to remember: the master password of a password manager, or the password that unlocks your computer or phone. Words are easier to remember and to type than a string of random characters. For everything else, let a password manager keep long random passwords.

The words have to be drawn by chance, not chosen by you. A line of a song, a quote or a sentence of your own is far weaker, because attackers try exactly those. If you do not like the words, draw a new passphrase instead of changing words by hand.

Official guidance agrees on length and randomness. NIST asks services to accept passwords of at least 64 characters and not to force rules about kinds of characters, and a password that is the only means of signing in should have at least 15 characters. A passphrase of several words meets that easily.

Frequently asked questions

Is it safe to make a passphrase on a website?

This generator makes it in your browser with the browser’s own source of randomness. The passphrase is not sent to a server or stored; only your settings stay in the browser. You can check this in the network panel of your browser, or load the page and then turn the internet off.

How many words should I use?

Six random words are already in the good band of this generator (66 bits with the lists of 2,048 words, 78 bits with the English one). The highest band, 100 bits, takes eight words of the English list or ten of the other lists. The more you can remember and type, the better.

Why only a few languages?

A list has to be free to use and checked, so it does not hold words that offend or are easy to mix up. We have such lists for English, Czech, Spanish and French. A list we could not check would make the generator worse, not better, so other languages wait until we find a good one.

Should I add symbols or change some letters?

There is no need. Length decides: one more word adds far more than a symbol. If a site asks for a capital letter or a digit, switch on those options; they do not make the passphrase stronger, they only satisfy the rule.

How it is calculated and where the data come from

How the result is calculated

The words are drawn from the cryptographic source of randomness of your browser (crypto.getRandomValues). Each word is chosen with the same probability from the whole list, and a draw that would favour some words is thrown away.
The words are drawn independently, so a word can come up twice. That keeps all passphrases equally likely, and their number is exactly the size of the list to the power of the number of words.
The strength in bits is the base-2 logarithm of that number, so every word adds the same bits: log2 of the size of the list (11 bits for 2,048 words, about 12.9 for 7,776). A drawn digit adds about 3.3 bits. The separator and the capital letters add nothing, because they are the same every time.
The time to guess is half of all the possibilities (the average) divided by the guesses per second an attacker manages, as in the password generator.
The bands are ours, not a standard: below 60 bits weak, 60 to 100 bits good, from 100 bits very strong.

Assumptions and limits

The strength holds only for a passphrase made by this generator, not for one you chose or changed yourself, and it assumes an attacker who knows the list and your settings.
We use only word lists with a published source and a free licence: English (EFF) and Czech, Spanish and French (BIP-39). Other languages will follow when there is a list we can check.
The speeds are tests of one graphics card. An attacker can use many, and a service can use a slower hash or limit the guesses, so the real time may be much shorter or much longer.
The generator does not know whether a passphrase has leaked, and it does not know the rules of a particular site, such as a maximum length.
Attacks on a person (phishing, malware) are not in the numbers, and a strong passphrase does not protect against them.

The online speed (10 guesses per second) is our example. The offline speeds are published tests: MD5 215.8 GH/s and bcrypt 255.3 kH/s on one NVIDIA RTX 5090 (hashcat v6.2.6). The word lists are the EFF Large Wordlist (English) and the BIP-39 lists (Czech, Spanish, French).

Data sources and the period they hold for

Every number a calculator starts with or computes from comes from one of the sources below. Series names are given as the publisher names them. Each row shows the period the data refer to and, where we record it, the day we downloaded them. Official data can be months old when they are published, so check the current figure before you decide.

Official: Published by a central bank, a statistical office, the European Union or another public body.
Research or industry data: A dataset of a university, an index provider, an industry association or a data vendor.
Reported: A figure of an official body that we know only from the press and did not check in the primary source. Treat it as approximate.
Example: A round number of ours, not a statistic. Replace it with your own.

Password attack speeds and recommendations

Show all 4 sources

Source	Period	Type
hashcat forum, RTX 5090 benchmark threadNVIDIA GeForce RTX 5090, hashcat v6.2.6, tuned run, MD5 (mode 0): 215.8 GH/s (fast hash)	2025-02downloaded 2026-10-07	Research or industry data
hashcat forum, RTX 5090 benchmark threadNVIDIA GeForce RTX 5090, hashcat v6.2.6, tuned run, bcrypt (mode 3200, 32 iterations): 255.3 kH/s (slow hash)	2025-02downloaded 2026-10-07	Research or industry data
ExampleOnline guessing against a login that limits the attempts: 10 guesses per second	2026	Example
NISTSP 800-63B-4, Digital Identity Guidelines: Authentication and Authenticator Management, section 3.1.1.2 Passwords	2025downloaded 2026-10-07	Official

Word lists for passphrases

Source	Period	Type
Electronic Frontier FoundationEFF Large Wordlist for Random Passphrases, 7,776 English words (CC BY 3.0 US; the dice numbers removed)	2016downloaded 2026-10-07	Research or industry data
Bitcoin Improvement ProposalsBIP-39 wordlists, 2,048 words each: Czech, Spanish, French (MIT licence; accents in the composed form)	currentdownloaded 2026-10-07	Research or industry data

Methodology text last reviewed 2026-10-06. Data last downloaded 2026-10-07. How we work with data and sources