Cryptographic source
Every value comes from crypto.getRandomValues(), the OS CSPRNG exposed by the browser. Math.random() is banned from this codebase: it is deterministic and reconstructible.
RANDOMNESS LAB / v1.0.0
Chance, made useful.
Tools that generate cryptographic randomness inside your browser. No account, no tracking, no result ever sent to the server.
crypto.getRandomValues()
rejection sampling
fisher–yates
wcag 2.1
rfc 4122
All tools
Eleven tools, one source
ALL IN-BROWSER
01
Password
Cryptographic randomness, not Math.random().
PASSWORD
02
Random number
Truly uniform: rejection sampling, zero modulo bias.
NUMERI
03
Dice
From d4 to d100, with total and histogram.
DADI
04
Coin flip
Heads or tails, with streaks and history.
MONETA
05
List picker
Paste the names, draw without replacement.
ESTRAZIONE
06
Teams
Balanced groups, no convenient choices.
SQUADRE
07
UUID
122 random bits, RFC 4122 layout.
UUID
08
Names
First and last names for tests, characters, prototypes.
NOMI
09
Palette
Computed harmonies, measured WCAG contrast.
PALETTE
10
Wheel
Chance decides, not the loudest voice.
RUOTA
11
Lottery
Six out of ninety, with the math on the honest side.
LOTTO
METHOD
Three rules, no exceptions
Rejection sampling
No modulo applied to a random integer: we draw until the value lands inside the largest exact multiple. Residual bias is zero, not negligible.
Local execution
Results are computed in the tab and never leave the device. The server only receives an anonymous counter: number of draws and bits served.
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ENTROPY
Why bits matter more than symbols
Entropy measures how many attempts it takes to guess a value. Adding symbols to the alphabet is cheap; adding length is expensive for the attacker.
Computed as log2(alphabet) × length. An attacker at one billion guesses per second needs about 10^13 years for 105 bits.
| VALUE | BITS | VERDICT |
|---|---|---|
| Password, 8 chars, 94 symbols | 52 bit | Weak |
| Password, 12 chars, 94 symbols | 79 bit | Adequate |
| Password, 16 chars, 94 symbols | 105 bit | Strong |
| Passphrase, 5 words, 7,776 list | 65 bit | Memorable |
| AES-128 key | 128 bit | Standard |
| UUID v4 | 122 bit | Unique |
Frequently asked
Questions that deserve a direct answer
Does the site store my results?
No. Draws happen in your browser. The server only receives draw counts and bits served, aggregated per tool: no values, no plaintext IP addresses (only a daily hash for rate limiting).
Do I need an account or a subscription?
No, and there will never be one. The site is funded by ads and affiliate links. Every tool stays free and unlimited.
Can I use it professionally?
Yes. Draws are suitable for raffles, testing, simulations and secret generation. No generator can protect you from a compromised device: if your system is infected, nothing here helps.
Can I verify the bias?
Yes. Every numeric tool shows the session histogram. Run ten thousand draws and watch: a uniform distribution stays flat.
How the site pays for itself
No paywall, no mandatory account. The page shows two ad slots and one sponsor block. If an affiliate link saves you money, the site earns a small commission at no extra cost to you.
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