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Password Generator

Create strong, random passwords with custom length and character sets.

Options

Generated Password

3y-offWsHd6XbK0[

Strength

Strength
Strong
104.9 bits of entropy
Strength meter
Alphabet size
87 chars
Possible combinations
103 bits
Time to crack (offline)
centuries

What is the Password Generator?

A strong password generator creates random, high-entropy passwords using a configurable mix of uppercase letters, lowercase letters, digits and symbols — protecting your accounts from brute-force and dictionary attacks.

Password Generator formula

Password entropy in bits = length × log2(charset_size). Lowercase-only (26 chars) at 12 characters = 12 × log2(26) ≈ 56 bits. Mixed case + digits + symbols (94 chars) at 16 characters = 16 × log2(94) ≈ 105 bits — strong enough to defeat any offline cracking attempt.

How to use the Password Generator calculator

  1. 1Set the desired password length (16+ characters recommended).
  2. 2Tick the character classes to include: uppercase, lowercase, digits, symbols.
  3. 3Optionally exclude ambiguous characters (l, I, 1, O, 0) for readability.
  4. 4Click Generate to create a new random password.
  5. 5Copy the result and paste it into a password manager — never reuse it across sites.

Example calculation

With all 4 character classes enabled at 16 characters, the generator produces passwords like 'K7#mQ2$vL9&pX5@n'. This password has an alphabet size of 94, giving entropy = 16 × log2(94) ≈ 105 bits — equivalent to a 1-in-10^31 chance of being guessed.

Frequently asked questions

What makes a strong password?
Length, randomness and uniqueness. Use at least 12–16 characters drawn from a mix of uppercase, lowercase, digits and symbols, generated by a cryptographic random source. Never reuse passwords across accounts.
How long should my password be?
Aim for 16+ characters with all character classes enabled, which gives ~100 bits of entropy — well beyond the reach of any modern GPU cracking rig. Length matters more than complexity: a 20-char lowercase password is stronger than an 8-char complex one.
How is password entropy calculated?
Entropy (bits) = length × log2(charset_size). A 12-character password using all 94 printable ASCII characters has 12 × 6.55 ≈ 79 bits of entropy. Each additional bit doubles the cracking difficulty.
Are random passwords safer than passphrases?
Both can be very secure. Random passwords are shorter for the same entropy; passphrases (4–6 random words) are easier to type and remember. For a password manager, use random passwords — you copy-paste them anyway.
Should I use a different password for every site?
Yes, always. If one site is breached, attackers try the leaked password against your other accounts (credential stuffing). A password manager plus this generator makes unique-per-site passwords effortless.

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