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CalculatorBuddy

Password Generator

Generate a strong random password on this device. Nothing is sent to a server — length, character sets, entropy, and strength stay in your browser.

Passwords are generated on this device with Web Crypto. Nothing is sent to a server or logged.

chars

Slider covers 4–100 characters. Type a number up to 5,000 for longer passwords.

Character sets

Printable punctuation except backslash. Use the options below to drop brackets or look-alike symbols.

Digit 1 is kept. Excluding characters lowers entropy.

A new password is generated whenever you change a control.

Generated password

Strong

Strength

Strong

Entropy
60.9 bits
Character pool
68

Build a random password on this device from the character sets you choose. Length, letters, numbers, symbols, and “no repeats” control the pool; the page shows the password, a five-bar strength meter, and entropy in bits. Nothing is sent across the network.

Formula

Each selected class (lower, upper, number, symbol) contributes one guaranteed character, then the rest of the length is drawn from the pooled alphabet, then the string is shuffled. Entropy for a password of length L from a pool of N characters:

H = L × log2(N)                 when repeats are allowed
H = log2(P(N, L))               when no character repeats

H is rounded to one decimal place. Default options use N = 68 (23 + 23 + 9 + 13).

Generation uses crypto.getRandomValues in your browser. Copy the password into a password manager rather than reusing it across sites.

Default character pool (N = 68)

SetDefault alphabet size
Lower case, ambiguous excluded23
Upper case, ambiguous excluded23
Numbers, 0 excluded (1 kept)9
Symbols, brackets and ambiguous excluded13
Total68

Strength from entropy

Entropy H (bits)StrengthBars
H < 36Very Weak1
36 ≤ H < 48Weak2
48 ≤ H < 60Good3
60 ≤ H < 120Strong4
H ≥ 120Very Strong5

Examples

Default 10-character password

All four sets on, ambiguous characters and brackets excluded, repeats allowed. Pool size 68, length 10, entropy 60.9 bits, strength Strong.

Numbers only, no zero

Include numbers only and exclude ambiguous characters. The pool is 123456789 (nine characters). A 9-character non-repeating password is a permutation of those digits; asking for 10 unique digits fails because the pool is too small.

Very strong, 20 characters

Keep the default 68-character pool and raise the length to 20. Entropy is about 121.7 bits (Very Strong). Prefer a password manager over memorizing a string this long.

Frequently asked questions

Is the generated password sent to a server?
No. The password is created in your browser with the Web Crypto API (crypto.getRandomValues). CalculatorBuddy never sends the password to an API, and it is not written to server logs. You can confirm this by using the page offline after it has loaded.
What is password entropy?
Entropy estimates how many guesses a brute-force search would need, in bits. With repeats allowed it is length × log2(pool size). With no repeated characters it is log2 of the permutation P(N, L). The default 10-character password from a 68-character pool is 60.9 bits (Strong).
Which characters are treated as ambiguous?
Look-alikes that are easy to confuse on screen: i, l, o and I, L, O, the digit 0, and punctuation such as pipe, backtick, quotes, and similar marks. Digit 1 is kept even though some labels list it. Excluding these characters makes a password easier to type and slightly weaker.
How is password strength classified?
Strength uses the rounded entropy. Below 36 bits is Very Weak, 36–48 is Weak, 48–60 is Good, 60–120 is Strong, and 120 bits or more is Very Strong. Longer passwords and larger character pools raise entropy.
Why can't I make a long password with no repeated characters?
That mode draws each character from the pool at most once, so the length cannot exceed the pool size (68 with the default options). Turn the option off, or include more character sets, to go longer.

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