Strong Password Generator
Secure, Random Passwords
Use the tool below to generate a strong, secure, random password instantly — no data sent to any server. Every password is created entirely inside your browser using your device’s cryptographic random number generator, the same technology used by banks and security software.
What Makes a Password Truly Secure?
Most people think a “strong” password just means adding a capital letter and a number to a word they already know. In practice, that’s not enough. Real password security comes down to two things: randomness and length.
Randomness — Why It Has to Be Truly Random
Passwords built around real words, dates, names, or patterns — even scrambled ones — are much easier for attackers to crack. Modern cracking tools don’t just try every combination; they work through dictionaries, common substitutions (like @ for a), and known patterns first. A password like P@ssw0rd! is cracked in seconds because it follows an extremely common pattern.
True randomness means no pattern at all. This generator uses your browser’s Web Crypto API (crypto.getRandomValues()), a cryptographically secure random number generator (CSPRNG) built into every modern browser. This is the same standard used by encryption software, VPNs, and operating systems to generate cryptographic keys. It is fundamentally different from the “random” functions used in general programming, which produce predictable sequences if an attacker knows the seed.
In plain terms: if you roll a fair die, no one can predict what number comes up. This generator does the digital equivalent — except with billions of possible faces on the die.
Length — The Single Biggest Factor
Every extra character you add doesn’t just increase difficulty by one step — it multiplies it. A 12-character random password drawn from letters, numbers, and symbols has roughly 80 bits of entropy, meaning an attacker would need to try 280 combinations on average to guess it. That’s over one septillion attempts. Adding just four more characters pushes this well beyond what any feasible attack can reach.
As a modern baseline, 16 characters or more is recommended for general accounts. For high-value targets — banking, email, password manager master passwords — aim for 20 characters or longer.
Character Variety — Why All Four Sets Matter
Using lowercase letters only gives you 26 possible characters per position. Adding uppercase doubles that to 52. Add digits and you’re at 62. Add symbols and you’re over 90. Each character set you include increases the “pool” an attacker has to search, compounding with every added character.
This generator also guarantees that at least one character from each set you enable will appear in the result — it doesn’t just make it probable, it enforces it. The characters are then shuffled using the same CSPRNG so their positions are unpredictable.
Understanding the Entropy Reading
The generator shows an entropy value in bits. This is a mathematical measure of how unpredictable your password is. Higher is better. Here’s a practical reference:
| Entropy | Strength | What It Means in Practice |
|---|---|---|
| Below 36 bits | Very Weak / Weak | Crackable in seconds to hours with modern hardware |
| 36 – 59 bits | Fair | Resists casual attacks; not suitable for sensitive accounts |
| 60 – 79 bits | Good | Solid for most everyday accounts |
| 80 – 99 bits | Strong | Exceeds current brute-force capability; recommended minimum for important accounts |
| 100+ bits | Very Strong | Far beyond any feasible attack with current or near-future technology |
These thresholds are aligned with NIST Special Publication 800-63B, the United States government’s digital identity guidelines, which are widely adopted as the security industry standard.
How to Use Your New Password Safely
A strong password is only as safe as how you handle it after generating it. Follow these practices to get the full benefit:
Use a Password Manager
A 20-character random password is impossible to memorise — and that’s exactly the point. The solution isn’t to make it simpler; it’s to use a password manager (such as Bitwarden, 1Password, or KeePass) that memorises it for you. You then only need to remember one strong master password. Password managers also auto-fill login forms, which protects you against phishing sites that use lookalike domains.
Never Reuse Passwords
If a service you use suffers a data breach and your password is exposed, attackers immediately try that same password on hundreds of other sites — a technique called credential stuffing. Using a unique password for every account means a breach at one site cannot compromise any other. Generate a fresh password here for each new account you create.
Enable Two-Factor Authentication (2FA)
A strong password protects you if an attacker doesn’t have it. Two-factor authentication (2FA) protects you even if they do. With 2FA enabled, logging in requires both your password and a one-time code from your phone or an authenticator app. Prefer app-based authenticators (like Google Authenticator or Authy) over SMS codes, which can be intercepted via SIM-swapping attacks.
Keep Passwords Out of Plain Text
Never save passwords in a plain text file, a spreadsheet, a notes app, or in your browser’s saved passwords without a master password protecting them. If that file is ever accessed — by malware, a shared computer, or a cloud sync breach — every account it lists is compromised at once. An encrypted password manager is the correct solution.
Check Whether Your Details Have Been Exposed
You can check whether your email address or passwords have appeared in known data breaches at HaveIBeenPwned.com. If any of your current passwords appear in breach databases, change them immediately — even if they appear “strong” by other measures.
Frequently Asked Questions
Is my generated password sent to your server?
No. Password generation happens entirely inside your browser using JavaScript. Nothing is transmitted over the network. You can verify this by generating a password while in aeroplane mode — it works identically.
What is a CSPRNG and why does it matter?
A Cryptographically Secure Pseudo-Random Number Generator (CSPRNG) is a random number source that meets strict mathematical requirements: its output must be statistically indistinguishable from true randomness, and knowing previous outputs must not let anyone predict future ones. The browser’s crypto.getRandomValues() API meets these requirements. Standard programming “random” functions — including JavaScript’s Math.random() — do not, and must never be used for security-sensitive tasks like password generation.
What does “exclude ambiguous characters” do?
Some characters are visually similar and easy to confuse when reading or typing a password: 0 (zero) and O (capital O), l (lowercase L), 1 (one), and I (capital i). Enabling this option removes them from the pool. It marginally reduces entropy, but can be useful if you ever need to type a password manually rather than paste it.
How long should my password actually be?
For general accounts: 16 characters minimum. For email, banking, or your password manager master password: 20 characters or more. Since you’re storing it in a password manager, length costs you nothing — there’s no practical reason not to use 24 or 32 characters for important accounts.
Are passphrases better than random passwords?
Passphrases — random strings of words like correct horse battery staple — can achieve equivalent entropy to a shorter random password and are significantly easier to memorise. They are an excellent choice for passwords you must type from memory, such as a password manager master password or a device login. For everything else stored in a password manager, a longer random password offers the best entropy per character.