Password Generator

What is Password Generator?

Free strong password generator. Generate secure random passwords with custom length, uppercase, lowercase, numbers, and symbols. Copy instantly. Instant generators for passwords, QR codes, barcodes, and more. TekPulse's Password Generator is completely free — no signup, no ads in results, and no data stored on our servers.

How to Use Password Generator Online

1. Set the desired password length (12+ characters strongly recommended)
2. Choose character sets: uppercase letters, lowercase letters, numbers, and special symbols
3. Click "Generate" — a cryptographically secure random password is created using the Web Crypto API
4. The strength meter shows Weak, Fair, Strong, or Very Strong based on entropy
5. Copy the password to clipboard — it is never sent to any server

Password Generator Formula & Calculation

Password strength is a function of two things: how many characters are possible at each position (the charset size) and how many positions there are (the length). The tool builds a character pool from your selected categories — uppercase (26), lowercase (26), numbers (10), symbols (32) — then uses crypto.getRandomValues() (the Web Crypto API's cryptographically secure random number generator, not Math.random()) to pick an unbiased index into that pool for every character.

Example: A 16-character password using all 4 categories (94-character pool) has entropy = 16 × log₂(94) ≈ 16 × 6.55 ≈ 105 bits — considered effectively uncrackable by brute force with current hardware. The same length using only lowercase (26 characters) drops to 16 × log₂(26) ≈ 75 bits — still strong, but a smaller pool means more guesses needed per bit, so excluding character types always weakens the password for the same length.

Key Factors That Affect Your Result

1. Length — The single biggest lever: each extra character multiplies the total possible combinations by the charset size. Going from 12 to 16 characters (full charset) takes entropy from ~79 bits to ~105 bits — a 2²⁶-fold increase in guesses required.
2. Character set breadth — Including all four categories (upper, lower, numbers, symbols = 94 characters) maximizes entropy per character versus using just one or two categories. Removing symbols because a site "doesn't allow them" meaningfully weakens the password.
3. True randomness source — crypto.getRandomValues() draws from the OS's cryptographically secure PRNG, unlike Math.random() which is predictable and unsuitable for security purposes. This matters because a predictable generator can make "random-looking" passwords guessable.
4. Ambiguous character exclusion — Removing 0/O/l/1/I (the "exclude ambiguous" option) shrinks the charset slightly, trading a small amount of entropy for fewer transcription errors when typing a password manually.

Why Use TekPulse Password Generator?