Settings
Password Generator
SecurityGenerate strong, random passwords with configurable length, character types, and bulk generation. Includes strength meter with entropy calculation.
Why use a random password generator?
Humans are notoriously bad at creating random passwords. We reuse patterns, substitute letters with predictable numbers (a→4, e→3), and choose words from a small vocabulary. Password cracking tools exploit these patterns — a dictionary attack can crack "P@ssw0rd!" in seconds despite its apparent complexity. A true random password generator uses cryptographically secure random numbers to select characters, making the result unpredictable to any attacker. This tool uses your browser's crypto.getRandomValues() API, the same entropy source used by security libraries and password managers.
Understanding password strength and entropy
Password strength is measured in bits of entropy — the number of yes/no decisions needed to guess the password. A password with N characters drawn from a pool of P possible characters has N × log₂(P) bits of entropy. For example, a 20-character password using uppercase, lowercase, numbers, and symbols (95 characters) has about 131 bits of entropy. Security experts recommend at least 80 bits for important accounts. The strength meter in this tool shows the entropy calculation so you can make informed decisions about the trade-off between length, character variety, and memorability.
Best practices for password security
Use a unique password for every account — if one service is breached, your other accounts stay safe. Generate passwords of at least 16 characters with mixed character types. Store them in a password manager rather than trying to memorize them. For master passwords that you must memorize, consider a passphrase of 4-6 random words. Enable two-factor authentication wherever possible as an additional layer of security. Never share passwords via email or chat — use a password manager's sharing feature instead.
Frequently Asked Questions
Are the generated passwords truly random?
Yes. Passwords are generated using your browser's crypto.getRandomValues() API, which provides cryptographically secure random numbers. No passwords are sent to or stored on any server.
What password length should I use?
For most accounts, 16-20 characters is an excellent balance of security and practicality. For highly sensitive accounts (email, banking, password manager master password), consider 24+ characters. The strength meter shows the entropy in bits — aim for at least 80 bits.
What does "exclude ambiguous characters" mean?
When enabled, this removes characters that look similar in many fonts: O (uppercase o) and 0 (zero), I (uppercase i) and l (lowercase L) and 1 (one). This is useful when you need to manually type the password or read it aloud, such as for Wi-Fi passwords shared with guests.
Part of 23+ free developer tools from BigDevSoon
Want to create your own tool?
Try our free Demo editor or start a 7-day trial with all features included.
No signup needed for demo editor
More Developer Tools
JWT Decoder
Decode and inspect JSON Web Tokens in real time. View header, payload, claims, and expiration status as you paste.
Hash Generator
Generate SHA-1, SHA-256, SHA-384, and SHA-512 hashes from text or files. Compare hashes, view all algorithms at once, and switch between cases.
JSON Formatter
Format, validate, and minify JSON data with line numbers. Real-time validation as you type.