🔑Strong Password Generator
Cryptographically secure passwords, generated in your browser. Nothing leaves your device.
0 — zero 1 — one I — capital I l — lowercase L O — capital O o — lowercase o
Need a password that's actually hard to crack? Our free Strong Password Generator creates one instantly, right in your browser. Choose your length and mix — uppercase, lowercase, numbers, and symbols — and it builds a random, high-strength password using your device's secure random generator. A live strength meter shows just how robust each one is, measured in bits of entropy, and a single click copies it ready to paste.
It's built with privacy first: every password is generated locally and never sent anywhere, stored, or logged, so what you create stays on your device. Switch on the option to skip easily-confused characters like l, 1, I, O, and 0 for passwords that are easier to type correctly, or generate several at once to pick your favourite. Whether you're setting up a new account, replacing a weak password, or creating credentials in bulk, you'll get genuinely strong, unique results every time.
Simply set your options and generate. No sign-up, no downloads, no limits — just secure passwords whenever you need them.
About the Strong Password Generator
How the randomness works
Web Crypto API
Passwords are built using window.crypto.getRandomValues — the browser's cryptographically secure random source. It is not predictable from prior outputs.
No modulo bias
Index selection uses rejection sampling so every character in the pool has an exactly equal probability of being chosen — no skew toward lower-indexed characters.
Guaranteed coverage
At least one character from each enabled set is placed first, then the remaining slots are filled randomly, and the whole result is shuffled using a secure Fisher-Yates algorithm.
No Math.random()
The standard Math.random() is a non-cryptographic pseudo-random generator unsuitable for security purposes. This tool never uses it.
Strength meter and entropy
The strength meter is calculated as entropy = length × log₂(pool size), where pool size is the number of unique characters available after applying your settings. This gives the number of bits of randomness — a measure of how many guesses an attacker would need on average.
Weak — under 40 bits
Feasible to crack with modern hardware. Short passwords or very small character sets. Consider increasing the length or enabling more character types.
Fair — 40–60 bits
Acceptable for low-risk accounts but not recommended for anything sensitive. A few more characters or an extra character set will push it into Strong territory.
Strong — 60–80 bits
Good for most accounts. Would take an impractical amount of time to brute-force with today's hardware, especially against a hashed password store.
Very Strong — 80+ bits
Suitable for high-value accounts and sensitive credentials. Computationally infeasible to crack by brute force on any realistic attacker's hardware.
Character set options
Uppercase (A–Z)
26 letters. Toggle off if a system requires case-insensitive passwords, though enabling it increases entropy significantly.
Lowercase (a–z)
26 letters. Usually the minimum requirement for readable passwords. Enables all standard ASCII letters.
Numbers (0–9)
10 digits. Adds a distinct character class, which many sites require and which contributes meaningfully to pool size.
Symbols (!@#…)
A broad set of printable punctuation and special characters. Dramatically increases pool size — the single biggest lever for entropy.
Exclude ambiguous
Removes I (capital I), l (lowercase L), 1 (one), O (capital O), 0 (zero), and o (lowercase o). Useful when you need to type the password by hand or read it aloud without ambiguity.
Generate multiple
Up to 10 passwords at once, each independently generated. Every one has its own Copy button so you can pick your favourite or use different ones per site.
Privacy guarantee
Every password is created in JavaScript running inside your browser tab. No network requests are made during generation — you can verify this in your browser's developer tools Network panel. There is no analytics attached to the generated values, no clipboard listener, and no localStorage or sessionStorage writes of password data.
The page itself may be served over HTTPS (standard for all Computezy pages), but the passwords you generate are never part of any request or response after the initial page load.
Frequently Asked Questions
How does the password generator work?
Choose a length and which character types to include, then click Generate. The tool builds a random password using your browser's cryptographically secure random number generator (the Web Crypto API), ensuring at least one character from each enabled set is present before filling the rest of the length and shuffling the result.
Is the password generator free to use?
Completely free — no sign-up, no downloads, no limits. Use it as many times as you like on any device.
Are my passwords sent anywhere or stored?
No. Every password is generated entirely in your browser. Nothing is sent to a server, logged, or saved anywhere — not even temporarily. Close the tab and the passwords are gone.
How random are the passwords?
They use the cryptographically secure random generator built into your browser (window.crypto.getRandomValues), not the basic Math.random() function. This is the same source used by secure applications for key generation and is genuinely unpredictable.
What makes a password strong?
Strength comes from length and the size of the character pool. The tool shows a strength meter based on entropy — measured in bits — which reflects the total number of possible password combinations. More bits means more combinations, which means harder to guess. Passwords above 60 bits are considered strong; above 80 bits are very strong.
Can I include or exclude symbols and ambiguous characters?
Yes. Toggle uppercase, lowercase, numbers, and symbols independently. You can also turn on the "Exclude ambiguous" option to remove characters that look similar — I (capital I), l (lowercase L), 1 (one), O (capital O), 0 (zero), and o (lowercase o) — making passwords easier to type or read aloud without mistakes.
How long should my password be?
Most security guidelines recommend at least 12–16 characters for general accounts and longer for sensitive ones. The strength meter gives you a live entropy reading so you can see exactly how strong each length is. For most purposes, 16 characters with a full character set gives over 100 bits of entropy — considered very strong.
Can I generate several passwords at once?
Yes. Set the "How many" field to up to 10 and click Generate. All passwords appear in a list, each with its own Copy button, so you can pick the one you like or use different ones for different accounts.
Does it work offline?
Once the page is loaded, passwords are generated entirely in your browser with no server connection needed. If your device goes offline mid-session the tool continues to work normally.
Does the password generator work on mobile?
Yes. The layout is fully responsive with easy-to-tap toggles and a one-tap Copy button. It works on phones, tablets, and desktops without any installation or sign-in.