Random Password Generator: Create Strong, Secure Passwords

Generate strong, random passwords with custom length and character types. See the password strength, entropy, and possible combinations instantly.

Mathematical Audit

How Password Strength Is Calculated

This tool builds a character pool from the types you select, then picks characters from that pool using a cryptographically secure random number generator. Strength is estimated using information entropy, the standard way security researchers measure how hard a password is to guess.

Character Pool Size = sum of selected sets (uppercase 26, lowercase 26, numbers 10, symbols ~32), minus any excluded ambiguous characters
Entropy (bits) = log2(Pool Size) x Password Length
Possible Combinations = 2^Entropy
Strength Rating: < 36 bits = Weak, 36-59 bits = Fair, 60-79 bits = Strong, 80+ bits = Very Strong
2026 guideline (CISA / NIST): randomly generated passwords should be at least 16 characters long

Length increases entropy exponentially, while adding more character types only increases it logarithmically. A longer password with fewer character types is often stronger than a short, complex one.

Operational Guide

How to Use the Random Password Generator

1

Set the password length

Use the slider or input to choose a length between 4 and 128 characters. 16 or more is recommended for most accounts.

2

Choose character types

Toggle uppercase letters, lowercase letters, numbers, and symbols on or off depending on the site's requirements.

3

Optionally exclude ambiguous characters

Turn on this option to remove easily confused characters like 0, O, 1, l, and I.

4

Review the strength meter

Check the entropy, character pool size, and strength rating to confirm the password is strong enough.

5

Copy and use a unique password

Click copy and paste the password into a password manager. Generate a new one for every account.

Real-World Scenario Example

"A user creating a new email account sets length to 16 with all character types enabled."

Inputs

length:16
includeUppercase:true
includeLowercase:true
includeNumbers:true
includeSymbols:true

Result

A 16-character password drawn from a 94-character pool, giving roughly 105 bits of entropy and a 'Very Strong' rating.

Important Disclaimer

All passwords are generated locally in your browser using a cryptographically secure random number generator and are never transmitted to or stored on our servers. Use a unique, randomly generated password for every account and store them in a reputable password manager.

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