Random Password Generator

Anatomy of a Strong Password

A strong password is one that is long, random, and drawn from a large pool of possible characters. The combination of these three factors determines how resistant a password is to both brute-force and dictionary attacks. Understanding what makes a password strong helps you configure this generator to produce credentials that match the security requirements of any platform or account type.

Use Random Passwords

Random passwords generated by a cryptographically secure source are fundamentally more secure than passwords chosen by humans. People tend to reuse words, patterns, keyboard walks, or personally meaningful information. Attackers exploit these tendencies with dictionary attacks, rule-based cracking, and social engineering. A truly random password drawn from a large charset contains no pattern an attacker can predict or exploit. This generator uses crypto.getRandomValues(), the same Web Cryptography API used by browsers for secure operations, to ensure every character is selected with cryptographic randomness rather than weak pseudorandom math.

How Password Generation Works

The generator builds a character set from the options you select: uppercase letters (A-Z, 26 chars), lowercase letters (a-z, 26 chars), digits (0-9, 10 chars), and symbols (!@#$%^&* and others, 26 chars). When you enable the "exclude ambiguous characters" option, visually similar characters such as 0 and O, I and l and 1 are removed to prevent transcription errors. The password is then constructed by generating a random 32-bit unsigned integer for each character position and taking that number modulo the charset length to select a character. The result is a password where each character is independently chosen and statistically uniform across all allowed characters.

Customize Length, Characters, and Complexity

The two most important variables in password security are length and character set size. This generator gives you direct control over both. Increasing password length multiplies the number of possible passwords exponentially. Expanding the character set achieves a similar effect. Together, these settings determine the password's entropy measured in bits, which quantifies how many guesses an attacker would need on average to crack the password by brute force.

How to Generate a Random Password in 5 Steps

Choosing Password Length and Complexity

The strength meter on this tool calculates entropy in bits using the formula: length multiplied by the base-2 logarithm of the charset size. A password with 80 or more bits of entropy is considered very strong against offline brute-force attacks with modern hardware. For context, a 16-character password using all four character types (88 chars in the charset) yields approximately 104 bits of entropy, well beyond the 80-bit threshold. A 12-character password using only lowercase letters yields only about 56 bits, which is considered fair but not strong for high-value accounts. When in doubt, longer is always better. Extending length by just a few characters dramatically increases the search space for any attacker. For critical accounts, use passwords of at least 20 characters with all character types enabled. To create a matching username for a new account, try our free username generator.

Creating Passwords for Accounts, Tokens, and Wi-Fi

Different use cases call for different password configurations. An online banking password, an API token, and a Wi-Fi network key each have different constraints and risk profiles. Understanding these differences helps you pick the right settings on the generator for each situation.

Creating Account Passwords

For user account passwords on websites, apps, and services, the most important rule is uniqueness. Every account should have a different password. Use this generator to create a unique password for each account, then store them in a password manager. A 16 to 20 character password with all character types enabled is appropriate for most accounts. For email, banking, and government portals where a breach would have severe consequences, aim for 24 characters or more. Avoid using the same password across multiple sites even if each individual password is strong, because a breach on one site could expose your credentials elsewhere. If you are setting up a new online business and need a domain alongside secure credentials, our domain generator can help you find an available domain name.

Generating API Keys

API keys and tokens need to be long, completely random, and composed entirely of alphanumeric characters in most cases since symbols can cause issues in HTTP headers, URL parameters, and configuration files. For API keys, use a length of 32 to 64 characters with uppercase, lowercase, and numbers enabled but symbols disabled. The "exclude ambiguous characters" option is also useful here to prevent transcription errors when copying keys between environments. For building the API endpoints that use these keys, our AI API generator can scaffold the authentication layer for your backend.

Password Recovery Codes

Many services provide one-time recovery codes or backup codes in case you lose access to your authenticator app or primary device. These codes need to be stored securely offline. You can generate a set of recovery-style tokens using this tool by setting the length to 8 to 12 characters with uppercase and numbers only (to keep them readable), excluding ambiguous characters, and generating 10 codes at once. Print or write these down and store them in a physically secure location separate from your devices. This approach mirrors what services like Google, GitHub, and Stripe use for their backup code systems.

Passphrase-Style Passwords with the AI Tab

A passphrase is a password made from multiple random words strung together, sometimes with numbers or symbols inserted. The AI tab in the password generator on the left lets you generate passphrase-style passwords with a specific theme, word count, and style. Passphrases are easier to remember than random character strings while still providing strong security through length. Switching to the Generate with AI tab opens a form where you can specify a theme, number of words, and output style. The AI then returns passphrase suggestions with entropy estimates for each.

16-Character Strong Password

A 16-character password using all four character types (uppercase, lowercase, numbers, symbols) produces approximately 104 bits of entropy from a charset of about 88 characters. This exceeds the 80-bit threshold for very strong passwords according to NIST guidelines. At 10 billion guesses per second, which is roughly the speed of a high-end GPU cracking offline hashes, a 104-bit password would take longer than the current age of the universe to crack by brute force. To generate one, set the slider to 16, enable all four character types, and click Generate Password.

Numbers-Only PIN Code

Some systems require numeric-only PINs for ATM cards, phone lock screens, or door codes. For a numeric PIN, disable uppercase, lowercase, and symbols, and set length to 6, 8, or 10 digits. Keep in mind that a 6-digit PIN has only 1 million possible values and should only be used where additional security measures such as lockouts after failed attempts are in place. For PINs that protect sensitive data, use a longer numeric string of 10 or more digits.

Passphrase-Style Password

Passphrases combine random words to achieve high entropy through length. A four-word passphrase drawn from a 7,776-word wordlist (the standard used by Diceware) has about 51 bits of entropy per word selection, or roughly 51 bits for the whole passphrase. Adding hyphens, capitalization, and a number between words increases entropy further and satisfies most "complexity" requirements. Use the AI tab in the left panel to generate themed passphrases. For example, entering "mountain hiking" as the theme with five words produces passphrases like "Summit-Trail-Cloud-8-Ridge" that are both secure and easier to remember than a random string like "kP3@xQ7!mNv2#eJw".

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