Password Generator – Strong, Random Passwords and Passphrases

A password generator that never sees your password

A password is only as private as the place where it was created. Many online generators produce the string on their server and send it to you, which means a third party briefly knows a secret that is supposed to be known by you alone. This generator works differently. The password is assembled by JavaScript running inside your own browser tab, using the secure random number generator built into your device. It is never transmitted, never logged and never saved; when you close the tab it is gone, so copy it into your password manager before you leave.

How to generate a strong password

1. Choose a password type: random characters for the strongest result, a passphrase of words for something you may need to type by hand, or a PIN for numeric locks.
2. Adjust the options. For random passwords that means the length and which character types to include; for a passphrase, the number of words and the separator.
3. Press Generate password. The strength meter shows the entropy in bits and a plain-language estimate of how long a determined attacker would need.
4. Use the Copy button next to the result, paste it into your password manager or the account settings page, and save it right away.

What makes a password strong?

Strength comes from unpredictability and length, not from clever substitutions. A password such as "P@ssw0rd!" follows a pattern attackers know by heart, whereas a string chosen completely at random has no pattern to exploit. The measure security people use is entropy, counted in bits. Each additional bit doubles the number of guesses an attacker needs. A password with 40 bits needs about a trillion guesses in the worst case, while 80 bits needs a trillion times a trillion, which is far beyond anything that can be tested in practice.

Modern guidance, such as the digital identity recommendations published by the US standards body NIST, has moved away from forcing odd character rules and frequent changes. It favors long passwords, allows pasting from password managers and suggests changing a password when there is evidence it has been exposed, not on a fixed schedule. Length is the cheapest strength you can buy: every extra character multiplies the work for an attacker.

Random characters, passphrase or PIN?

Random characters

This is the best choice for anything stored in a password manager, because you will never need to remember it. A 16-character mix of lowercase letters, uppercase letters, numbers and symbols gives roughly 103 bits of entropy. The generator also guarantees at least one character from every set you tick, so sites with composition rules accept the result on the first try. If you ever have to read a password aloud or type it from a printed sheet, tick Exclude look-alike characters to remove 0, O, 1, l, I and the vertical bar, which are easy to confuse.

Passphrase

A passphrase strings together several random common words, such as "Meadow-Lantern-Copper-Orbit-Willow-Rabbit". It is easier to remember and to type on a phone than a jumble of symbols, which makes it ideal for the few passwords you must know by heart: your computer login, your password manager's master password or your disk encryption key. The key is that the words are chosen by the computer, not by you; a phrase you invent, such as a favorite quote, is far weaker than it looks. Each word from this tool's list adds about 9 bits, so use six words as a minimum and eight or more for something you want to protect for years.

PIN

A PIN is short by design, so the meter honestly rates it as weak. That is acceptable for phone and bank-card locks because the device or bank limits the number of attempts. Do not use a PIN as the only protection of an online account.

How the entropy and crack-time estimates work

Entropy is calculated from the size of the pool and the length: the logarithm of the pool size, multiplied by the number of characters. For passphrases the pool is the word list. The crack-time line assumes an attacker who has stolen a database and can test ten billion guesses per second, which is a generous figure for a single powerful graphics card against a fast hash function. Real systems that use slow, salted hashing such as bcrypt or Argon2 are many orders of magnitude harder to attack, and live login forms usually block repeated guesses. The number is therefore a conservative teaching aid, not a guarantee.

Where the randomness comes from

The generator uses the browser's cryptographically secure random source, crypto.getRandomValues, the same facility that secures HTTPS connections. It does not use the ordinary Math.random function, which is predictable and unsuitable for secrets. To pick a number in a range, the code rejects values that would cause bias, so every character or word has exactly the same chance of being chosen. The tool then shuffles the guaranteed characters into random positions.

Habits that matter more than the generator

• Use a different password for every account. Reuse is the biggest real-world risk, because one leaked site exposes all the others.
• Store passwords in a reputable password manager and protect it with a long passphrase generated here.
• Turn on two-factor authentication wherever it is offered, preferably with an authenticator app or a hardware key.
• Avoid sharing passwords by email or chat. If you must share access, use the sharing feature of your password manager.
• Remember the clipboard. Other programs on your device may read copied text, so paste the password promptly and clear the clipboard afterwards if you are on a shared computer.

Nothing here is stored or sent, and the page works offline after loading, so you can generate a password even when you are not connected.

Frequently asked questions

Related tools

• Zip Files (Create & Extract)
• QR Code Generator
• Unit Converter
• Percentage Calculator
• All free tools (English hub)

Need custom software, a faster website or help with digital projects? The team at Bilişim Ajans can help.