Random Password Generator
Generate secure, strong, random passwords instantly. Customize length and character types, exclude ambiguous characters, and see password strength and entropy with our free online password generator.
Your Password
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Pool size: 89 characters
Character Types
Password Entropy Formula
Where Lis the password length and Nis the number of possible characters in the pool. Higher entropy means the password is harder to crack through brute force.
How to Use
- 1
Set your desired password length using the slider — longer passwords are exponentially harder to crack, so 16 characters or more is recommended
- 2
Choose which character types to include: lowercase letters, uppercase letters, numbers, and symbols. Using all four types maximizes the character pool and strengthens your password
- 3
Optionally toggle "Exclude ambiguous characters" to remove easily confused characters like I, l, 1, O, and 0 — helpful when you need to read or type the password manually
- 4
Click Regenerate to create a new random password, or it generates automatically when you change the settings
- 5
Review the password strength indicator and entropy value — aim for at least 60 bits of entropy for a strong password
- 6
Click Copy to copy the password to your clipboard, then paste it into your account or password manager
- 7
Understanding the key inputs — password length is the single biggest factor in strength; each additional character multiplies the number of possible combinations by the pool size
- 8
Interpreting the results — entropy is measured in bits and estimates how many guesses a brute-force attack would need on average; 128 bits is considered extremely secure against any realistic attack
Examples
Good Examples
Strong 16-character password with all character types
16 chars × 4 types (94-char pool) ≈ 104.9 bits entropy — Strong, safe for most online accountsMaximum security 32-character password
32 chars × 94-char pool ≈ 209.8 bits entropy — Very Strong, suitable for password manager vaults and encryption keysMemorable-friendly password with ambiguous characters excluded
20 chars × ~83-char pool ≈ 127.6 bits entropy — Strong and easier to read or type without confusionPIN-style numeric password for a 6-digit lock
6 chars × numbers only (10-char pool) = 19.9 bits entropy — Very Weak, only suitable for low-security PINsBest password for a banking account
Use 20+ characters with all four types enabled → ~130 bits entropy, far beyond what any brute-force attack can crackBad Examples
Using a short 8-character password
8 chars × 94-char pool ≈ 52.4 bits — Fair at best, and vulnerable to modern GPU brute-force attacks in hoursNumbers-only password for a sensitive account
8 digits × 10-char pool = 26.6 bits — Very Weak, crackable in secondsReusing one generated password across multiple accounts
No matter how strong the password is, a single breach on any site compromises every account that shares itExcluding all symbols to make it easier to type
Removing symbols shrinks the pool from 94 to 62 characters, lowering entropy by ~0.6 bits per characterCommon Mistakes
- Using a password that is too short — anything under 12 characters is increasingly vulnerable to brute-force attacks as hardware improves
- Reusing the same password across multiple accounts — one breach exposes every account that shares the password
- Including personal information like names, birthdays, or pet names — these are easy for attackers to guess or find on social media
- Choosing passwords that match common formats like calendar dates, phone numbers, or license plates — these are on every password blacklist
- Confusing password strength with password length alone — a 20-character numbers-only password is weaker than a 12-character password using all character types
- Saving generated passwords in plain text files like a Word document or sticky note — use a dedicated password manager instead
- Forgetting that excluding ambiguous characters lowers entropy slightly — only use it when readability matters more than maximum strength
- Assuming a "Strong" rating means the password is unforgettable — even strong passwords should be stored in a password manager because they are intentionally random
Frequently Asked Questions
How do I generate a strong random password?
Use a password generator that draws from a cryptographically secure random source. Set the length to at least 16 characters and enable all four character types — lowercase, uppercase, numbers, and symbols — to maximize the character pool. This generator creates the password entirely in your browser, so it is never transmitted over the internet.
How is password strength calculated?
Password strength is estimated from password entropy, which is measured in bits using the formula: , where is the password length and is the size of the character pool. Higher entropy means more possible combinations and a harder-to-crack password. A password with 60+ bits is considered Strong, and 128+ bits is Very Strong.
How long should my password be?
For most online accounts, use at least 16 characters. For highly sensitive accounts such as banking or your password manager vault, use 20 characters or more. Every additional character multiplies the number of possible combinations by the pool size, so length is the single biggest factor in password strength.
What is password entropy and how many bits do I need?
Password entropy measures the unpredictability of a password in bits. In a brute-force attack, a password with bits requires up to guesses to exhaust all possibilities. Aim for at least 60 bits for everyday accounts and 100 bits or more for sensitive accounts. 128 bits is considered extremely secure against any realistic attack.
Are online password generators safe to use?
A trustworthy online password generator creates the password locally in your browser using a cryptographically secure random number source, so the password is never sent across the internet. This generator uses the Web Crypto API (crypto.getRandomValues) with rejection sampling to avoid modulo bias, making the output suitable for real-world use.
What are ambiguous characters and should I exclude them?
Ambiguous characters are characters that look alike and are easy to confuse when reading or typing, such as uppercase I, lowercase l, and the number 1, or uppercase O and the number 0. Excluding them is helpful when you must manually type or read a password from a screen. Note that removing characters shrinks the pool slightly, which lowers entropy, so only use this option when readability matters more than maximum strength.
Random password vs passphrase — which is better?
A random password generated by a tool has maximum entropy and no guessable patterns, making it the most secure option. The trade-off is that it is impossible to memorize, so it should be stored in a password manager. A passphrase of four or more unrelated words is longer and easier to remember while still achieving high entropy, making it a good choice when you must memorize the password yourself.
Should I reuse the same strong password across multiple accounts?
No. Even a very strong password becomes a liability if it is reused, because a single data breach on one site would expose every account that shares it. The best practice is to use a unique generated password for each account and store them all in a password manager, so you never need to memorize them.