Password Generator

0 bits of entropy · weak

Estimated time to crack: — (average, offline attack at 10 billion guesses per second)

Length

16

Character sets

Press Space to regenerate, C to copy

Bulk output is useful for provisioning accounts or seeding a password manager import. The list exists only in this text box until you copy or download it.

    100% client-side Web Crypto CSPRNG No storage, no tracking of passwords Works offline
    Private by design

    A password generator that never sees your passwords

    Create cryptographically secure passwords, memorable passphrases, and PINs directly in your browser. Nothing you generate ever leaves your device, and you can verify that yourself: the page keeps working with your internet connection switched off. Every estimate shown above comes from published entropy math, not a black box, and the full formula is explained in the sections below.

    Quick answer

    What makes a password strong?

    A strong password is long, random, and unique. Length matters most: a randomly generated 16-character password drawn from letters, digits, and symbols has about 105 bits of entropy, which puts a brute-force attack far beyond practical reach. Randomness must come from a generator, not a human, and every account needs its own password so one breach cannot unlock the rest.

    Length figures derive from entropy math shown in the entropy section below. Guidance on length over complexity follows NIST Special Publication 800-63B.

    Password strength checker

    How strong is my password?

    Type or paste a password to estimate its entropy and the time a brute-force attack would need. The check runs entirely in your browser. Nothing is sent anywhere, logged, or stored, and the field never autosaves.

    Length0
    Character pool0
    Entropy0 bits
    Crack time—

    This estimate assumes the password is random. Real passwords built from names, dates, and dictionary words fall to pattern-based attacks far faster than raw entropy suggests, so treat this number as an upper bound. Never test a password you actively use on any website, including this one; test a similar pattern instead.

    Brute-force data

    How long does it take to crack a password?

    The table shows the average time to brute-force a truly random password at 10 billion guesses per second, a rate achievable by a multi-GPU rig attacking a fast hash such as MD5 or NTLM. Slow hashes like bcrypt or Argon2 multiply every figure by thousands. All values are computed directly from pool size and length, so you can verify them yourself with the formula in the entropy section.

    Average crack time = (pool size ^ length) / 2 / 10,000,000,000 guesses per second. Figures rounded. Random passwords only; human-chosen passwords fall much faster to dictionary and pattern attacks.
    LengthLowercase only (26)Upper + lower (52)Letters + digits (62)All printable (94)
    8 characters10 seconds45 minutes3 hours3.5 days
    10 characters2 hours83 days1.3 years85 years
    12 characters55 days618 years5,100 years755,000 years
    14 characters102 years1.7 million years19.6 million years6.7 billion years
    16 characters69,000 years4.5 billion years76 billion years59 trillion years
    20 characters8 billion years10^17 years10^19 years10^21 years
    The math

    Password entropy explained

    Entropy measures how unpredictable a password is, in bits. The formula is simple: entropy = length × log₂(pool size). Each extra bit doubles the number of guesses an attacker needs, which is why length beats complexity: adding one character to a full-charset password adds 6.55 bits, multiplying the attacker's work by roughly 94.

    Password entropy by length and character set Line chart showing entropy in bits for passwords from 6 to 24 characters. The 94-character set reaches 80 bits at around 13 characters, the 62-character set at around 14, and lowercase-only at 17. 040 80120 160200 69 1215 1821 24 Password length (characters) Entropy (bits) 80-bit strong threshold 12 chars ≈ 79 bits
    All printable, 94 chars (6.55 bits/char) Letters + digits, 62 chars (5.95 bits/char) Lowercase only, 26 chars (4.70 bits/char)
    Bits per character = log₂(pool size). Reaching 80 bits is a widely used benchmark for resisting offline attacks.
    Character setPool sizeBits per characterLength needed for 80 bits
    Digits only103.3225
    Lowercase letters264.7018
    Upper + lowercase525.7015
    Letters + digits625.9514
    All printable ASCII946.5513
    Diceware word (EFF long list)7,776 words12.9 per word7 words
    Feature comparison

    What most online password generators are missing

    We audited the typical feature set of popular online generators before building this one. Most offer a single random mode with a length slider and stop there. Here is what this tool adds.

    Typical generator refers to the common feature set across widely used free online password generator pages as of 2026. Individual tools vary; verify against the specific tool you compare.
    CapabilityTypical online generatorThis tool
    Random passwords with charset controlYesYes
    Diceware-style passphrasesRareYes, with separators and casing
    Pronounceable modeRareYes, with honest entropy reporting
    PIN generatorSometimesYes
    Live entropy in bitsAlmost neverYes, on every keystroke
    Crack-time estimate with stated assumptionsRare, assumptions hiddenYes, formula published on page
    Bulk generation with copy and .txt exportAlmost neverUp to 100 at once
    Color-coded character classes for easy transcriptionNoYes
    Exclude look-alike charactersSometimesYes
    Custom character injectionRareYes
    Built-in strength checkerSeparate page, often server-sideSame page, fully local
    Works offlineSometimesYes, single self-contained page
    Unbiased randomness (rejection sampling)UnverifiableYes, view source to confirm
    Step-by-step guide

    How to create a strong password

    Follow these five steps to generate and store a password that will outlast any realistic brute-force attack.

    Pick a length of 16 characters or more

    Set the length slider to at least 16. At full charset that yields about 105 bits of entropy, comfortably above the 80-bit benchmark for resisting offline attacks.

    Enable all four character sets

    Keep lowercase, uppercase, digits, and symbols switched on. A larger pool raises bits per character, so the same length buys more security.

    Generate and copy the password

    Click Generate new password, then use the copy button or press C. The password is produced by your browser's cryptographic random number generator, never by a server.

    Store it in a password manager

    Paste the password into a reputable password manager rather than a note or spreadsheet. A manager removes the need to memorize anything, which removes the temptation to reuse.

    Never reuse it, and add two-factor authentication

    Use one unique password per account so a breach at one service cannot cascade. Turn on two-factor authentication wherever it is offered; it protects you even if the password leaks.

    Standards

    What NIST recommends for passwords

    NIST Special Publication 800-63B sets the password guidance used across US government systems and widely adopted by industry. Its key points overturn several habits that older corporate policies still enforce.

    SP 800-63B

    Length over complexity rules

    NIST advises against forcing arbitrary composition rules such as one uppercase, one digit, one symbol. People satisfy them predictably (Password1!), which helps attackers more than it helps defenders. Length and randomness are the recommended controls.

    SP 800-63B

    No forced periodic resets

    Scheduled password expiry pushes people toward incremental changes like appending a counter. NIST recommends requiring a change only when there is evidence of compromise.

    SP 800-63B

    Screen against breached lists

    Verifiers should check new passwords against lists of known compromised passwords and reject matches. A perfectly formatted password that already sits in a breach corpus offers no protection.

    SP 800-63B

    Allow long passphrases and paste

    Systems should accept passwords of at least 64 characters, permit spaces, and allow pasting so password managers work smoothly. Blocking paste actively harms security.

    Infographic

    Random password vs passphrase: which should you use?

    Both reach strong entropy. The right choice depends on whether a password manager types it for you or you type it yourself.

    Comparison of a random password and a diceware passphrase Two panels compare a 16-character random password at 105 bits of entropy, best for password managers, with a 7-word passphrase at about 90 bits using the EFF list, best for typed master passwords. Random password Passphrase Kv9#mQ2$xPw7!nRz orbit-maple-crisp-vivid-lunar ENTROPY (16 chars, pool 94) ENTROPY (7 words, EFF list) ~105 bits ~90 bits + Maximum entropy per character + Ideal inside a password manager + Short enough for tight length caps − Nearly impossible to memorize − Painful to type on a phone or TV + Easy to memorize and say aloud + Fast to type on any keyboard + Scales: each word adds ~12.9 bits − Longer string overall − Some sites cap length too low Best for: everything in a manager Best for: master passwords you type Entropy bars drawn to a common 120-bit scale. EFF long list: 7,776 words, log2(7776) = 12.9 bits per word.
    What to avoid

    Six password mistakes that defeat any generator

    A perfect password handled badly protects nothing. These are the failure modes that show up over and over in real breach postmortems.

    Reusing one password everywhere

    Credential stuffing attacks replay leaked email and password pairs against hundreds of other sites. One breach becomes many.

    Generate a unique password per account and let a manager remember them.

    Personal information as a base

    Names, birthdays, pets, and teams are the first candidates in any targeted attack and appear in every cracking wordlist.

    Use output from a random generator with no connection to your life.

    Predictable substitutions

    P@ssw0rd! feels clever but l33t substitutions are standard rules in cracking tools and add almost no real entropy.

    Add genuine length instead of decorating a dictionary word.

    Keyboard walks

    qwerty, 1q2w3e4r, and zxcvbn patterns are in every wordlist precisely because they feel random while being anything but.

    Trust the generator, not your fingers.

    Storing passwords in plain text

    A notes app, a spreadsheet, or an email draft turns one device compromise into a full account takeover kit.

    Use an encrypted password manager protected by a strong passphrase.

    Skipping two-factor authentication

    Even strong passwords can leak through phishing or a breached service. Without a second factor, the password is the whole defense.

    Enable an authenticator app or hardware key on important accounts.
    Glossary

    Password security terms, defined

    Entropy
    A measure of unpredictability in bits. Each additional bit doubles the number of guesses required to exhaust the search space. Calculated as length multiplied by log base 2 of the character pool size.
    CSPRNG
    Cryptographically secure pseudorandom number generator. A random source designed so its output cannot be predicted even by an attacker who sees previous outputs. Browsers expose one through the Web Crypto API as crypto.getRandomValues.
    Brute-force attack
    Trying every possible combination until the right one is found. Feasible against short passwords and fast hashes; infeasible against long random passwords.
    Dictionary attack
    Trying words, names, and known leaked passwords, plus common mutations, before resorting to brute force. This is why human-chosen passwords fall faster than their length suggests.
    Credential stuffing
    Replaying username and password pairs leaked from one breach against other services, exploiting password reuse.
    Diceware
    A passphrase method that selects words at random from a fixed list, traditionally with physical dice. The EFF long list contains 7,776 words, giving about 12.9 bits of entropy per word.
    Rejection sampling
    A technique for converting raw random bytes into unbiased choices from a pool whose size does not divide evenly into 256. Naive modulo arithmetic skews results toward early characters; rejection sampling discards out-of-range bytes instead.
    Password hashing
    Storing a one-way transformation of a password instead of the password itself. Slow, salted algorithms such as bcrypt, scrypt, and Argon2 are designed to make offline guessing expensive.
    FAQ

    Password generator questions, answered

    Is this password generator safe to use?
    Yes. Every password is generated locally in your browser using the Web Crypto API. No password is transmitted, logged, or stored by this page, and there are no analytics attached to the generator itself. You can disconnect from the internet after the page loads and it will keep working, which is the simplest way to verify the claim. The page is a single self-contained file, so anyone can read the source.
    What is the best password length in 2026?
    Use 16 characters or more for passwords stored in a password manager, and a passphrase of at least 7 random words for anything you must memorize. A random 16-character password from the full printable set carries about 105 bits of entropy, far beyond what brute force can reach. See the crack time table for the full breakdown by length and character set.
    Should I use a random password or a passphrase?
    Use random passwords for accounts your password manager fills automatically, and a passphrase for the few secrets you type by hand, such as the manager's own master password or a device login. Both reach strong entropy; the difference is purely ergonomic. The comparison infographic above lays out the trade-offs.
    How does this generator create randomness?
    It calls crypto.getRandomValues, the browser's cryptographically secure random number generator, and converts the raw bytes into characters using rejection sampling so every character in the pool is equally likely. Math.random is never used because it is predictable and unsuitable for secrets.
    Are the crack time estimates accurate?
    They are exact for the stated model: a brute-force attack at 10 billion guesses per second against a truly random password, taking on average half the keyspace. Real-world times vary enormously with the hash algorithm. Fast hashes like MD5 fall near the modeled rate; slow hashes like bcrypt or Argon2 can be thousands of times slower for attackers. Human-chosen passwords also fall much faster than the model because attackers try dictionaries and patterns first.
    Why does the passphrase mode say 8 bits per word?
    This page embeds a 256-word list to stay fully self-contained, and log base 2 of 256 is exactly 8 bits per word. The classic EFF long list has 7,776 words, or about 12.9 bits per word. Either way the entropy shown is honest for the list actually used, so add more words rather than assuming a bigger list.
    Is it safe to type a real password into the strength checker?
    The checker runs entirely on your device and sends nothing anywhere, but the safest habit is still to never type an active password into any website, including this one. Test a password with the same structure instead: same length, same mix of character types.
    What characters should a strong password include?
    Include all four sets when the site allows it: lowercase, uppercase, digits, and symbols, for a 94-character pool worth 6.55 bits per character. If a site restricts symbols, compensate with length: a 14-character letters-and-digits password roughly matches a 13-character full-charset one.
    How often should I change my passwords?
    Only when there is a reason: a breach notification, a phishing scare, a shared password, or a device you no longer trust. NIST SP 800-63B recommends against forced periodic resets because they push people toward weak incremental changes. A strong unique password does not expire on a calendar.
    Can I generate passwords for my whole team at once?
    Yes. Open Bulk generate under the main button, choose a quantity up to 100, and export the list as a .txt file or copy it for a password manager import. The list lives only in the text box on your screen until you save it.
    Do password generators work offline?
    This one does. The entire tool, including the word list and the entropy math, ships in one HTML file with no server calls after load. Save the page locally and it functions as an offline password generator on any modern browser.
    What makes a password weak even if it looks complex?
    Predictability. P@ssw0rd2026! satisfies every composition rule yet sits in cracking wordlists because it is a dictionary word with standard substitutions and a date. Complexity rules measure appearance; entropy measures reality. A password is strong only if it was selected at random from a large space.