Password Generator

How to Use the Password Generator

Choose length and character options, generate one or more passwords in your browser, then copy or regenerate as needed.

1. Set length between 8 and 128 characters (default 16).
2. Enable or disable character sets (uppercase, lowercase, numbers, symbols) as needed — at least one type must stay selected.
3. Optionally enable Exclude ambiguous characters (O, 0, I, l, 1).
4. Press Generate Password.
5. Copy the password or generate again for a new result.

Methodology & NIST entropy standards

The password generator utilizes the browser's cryptographic pseudo-random number generator (CSPRNG via window.crypto.getRandomValues) combined with rejection sampling to eliminate modulo bias across custom character alphabets.

Entropy is calculated pursuant to NIST SP 800-63B guidelines: E = L × log₂(N), where L is password length and N is the character pool cardinality. A 16-character password drawn from an alphabet of 94 symbols delivers over 104 bits of search space entropy.

Worked password generation example

• Input settings: Length = 16 characters; Include Uppercase, Lowercase, Numbers, and Symbols; Exclude ambiguous characters.
• Available character pool: 90 characters (ambiguous characters omitted).
• Entropy evaluation: 16 × log₂(90) = 103.87 bits.
• Sample generated result: xK8$vP2#mQ9!wZ5&
• Security assurance: Generated strictly on the local CPU without transmitting the secret across the network.

Cryptographically secure randomness

This tool uses crypto.getRandomValues with rejection sampling for unbiased character selection. It does not use Math.random. Passwords are assembled and shuffled entirely in your browser.

Entropy, length, and complexity

Both length and character-set size matter. A longer password from a larger pool is generally harder to guess. The on-page strength label is only an estimate from length and charset size — not a guarantee against cracking, and not a claim of “unbreakable” or “military grade” security.

Ambiguous characters

When Exclude ambiguous characters is on, the generator omits O, 0, I, l, and 1 so passwords are easier to type or read aloud. Turning this on slightly reduces the character pool for the same length.

Common mistakes

• Reusing the same password on many sites.
• Using names, birthdays, or dictionary words alone.
• Sharing passwords over insecure channels (email, chat).

Privacy

Generated passwords are not sent to ToolsLibrary servers and are not stored in tool history, analytics, or remote databases. Closing or resetting the tool clears the on-screen value.

Limitations

This tool does not store passwords, sync across devices, or manage accounts. Prefer a password manager for long-term storage. Security after you copy a password depends on how you store and use it.

FAQ

Is this password generator secure?

Passwords are generated locally with the browser’s cryptographically secure random number generator (crypto.getRandomValues). Strength after you copy or store a password elsewhere depends on how you use it — ToolsLibrary does not claim passwords are unbreakable.

How are passwords generated?

Selected character types form a pool. The tool picks at least one character from each selected type (when length allows), fills the rest securely, then shuffles with crypto.getRandomValues. Math.random is not used.

Are passwords sent to a server?

No. Generation runs entirely in your browser. Passwords are not uploaded to ToolsLibrary servers.

Can I generate a password with symbols?

Yes. Enable Symbols in the options. You can also turn symbols off if a site rejects them.

Can I exclude ambiguous characters?

Yes. Enable “Exclude ambiguous characters” to omit O, 0, I, l, and 1 so passwords are easier to read aloud or type.

How long should a password be?

Longer is generally stronger. Many experts recommend at least 12–16 characters when using a mixed character set. Use a password manager for unique passwords per site. This tool allows 8–128 characters (default 16).

Can I generate a password without numbers?

Yes. Uncheck Numbers (and any other types you do not want). At least one character type must remain selected.

Are generated passwords stored?

No. ToolsLibrary does not store generated passwords in history, analytics, or a database. Clearing or leaving the page discards the password from this tool’s UI.

Should I use a password manager?

Yes when practical. A password manager helps you store unique passwords securely. This generator creates candidates; it does not replace a manager or protect passwords after you copy them.