ГСЧ randomness lab
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Random number
Cryptographic generator · no sign-up

Randomness you can trust

Numbers, a coin, dice, a wheel, a list picker and giveaways with verifiable results. Computed in your browser — instantly, with no sign-up and no data sent to a server.

Generate a number Run a giveaway
CSPRNG, not Math.random instant result data never leaves the browser
Quick generator
— from 1 to 100
—
Heads or tails?
Roll the dice
Who is first?
No sign-up · data never leaves your browser All settings

14 tools

Everything randomness is for

From a single number to a giveaway with a public hash. Each tool solves one task, with no unnecessary settings.

Poker lab
14 tools
Numbers

Random Number Generator

Any number in any range

instantly
Coin and dice

Coin Flip

Heads or tails online

instantly
Coin and dice

Dice Roller

d4–d20 for tabletop games

instantly
Random choice

Random Pick from a List

Pick a winner from names

instantly
Random choice

Fortune Wheel

Spin and let it choose

2–30 с
Random choice

Magic 8 Ball

Ask a question, get an answer

~3 s
Random choice

Random Teams

Split players into teams

instantly
Lotteries

Lottery Numbers

6/45, 5/36, Keno

instantly
Giveaways

Prize Giveaway

A draw you can verify

instantly
Giveaways

Verify a Giveaway

Confirm the fairness

instantly
Utilities

Password Generator

Strong passwords and phrases

instantly
Utilities

UUID and Tokens

Identifiers in bulk

instantly
Utilities

Random Color

HEX, RGB and palettes

instantly
Utilities

Random Date

Date and time in a range

instantly

Our generator

Three entropy sources instead of one

The public drand beacon, physical entropy from your movements and a cryptographic CSPRNG are mixed with SHA-256. The scheme is open and the quality can be tested in one click.

How it works Test the quality

Honesty

Giveaway,
which cannot be adjusted

The organizer publishes the hash of the secret before the start. After the draw, the secret is revealed — and each participant recalculates the winners themselves.

  1. 1
    Public hash

    The site generates a random secret and shows the SHA-256 — a promise that cannot be changed retroactively.

  2. 2
    List of participants

    Participants are recorded in an open form. The order of the lines does not affect the result.

  3. 3
    Disclosure of a secret

    Winners are calculated as SHA-256(secret : number : name). Verification is available to everyone.

Start a giveaway Check the result
Entropy 30 %

Requesting the public randomness beacon…

CSPRNG Your movements Beacon
Commit
The SHA-256 of the secret is published before the draw 9f2c41e7b8a3d06f5c1e9a7b3d84f20c6e5a1b9d7f3c8e2a4b6d0f1c3e5a7b9d
Reveal
The secret is revealed afterwards k3j9x2m7q1w8e5r0t4y6u2i9o3p7a1s5

The hash matches the secret → the result is honest. Verification takes one second.

Since 2011

Poker Laboratory

The very simulators that the site started with: edge, bad beats, variance. Now — with proper graphs and without page reloads.

All simulators
Poker

Coin-Flip Duel

Players with a percentage edge

~0.5 s
Poker

Preflop All-in

Equity and bad-beat simulator

~1 s
Poker

Card Dealer

Deck, players, board

instantly
Poker

Hyper-Turbo SNG

Bankroll across tournaments

~1 s
Poker

Tournament Variance

500 players, one chart

~2 s

Cryptographic source

crypto.getRandomValues — the same generator that protects banking connections. Without 'time-based randomness'.

Everything in the browser

Lists, numbers, and results are calculated on your device. No data is sent and no server response is awaited.

No sign-up

No accounts, no generation limits, no advertising beggars. Open it — and you can start generating right away.

Verifiable draws

Commit-reveal scheme and SHA-256: the result cannot be resubmitted without changing the published hash.

Questions

Briefly about the main thing

Is this a gambling site?
No. ГСЧ is an information and entertainment service of random number generators and probability simulators. It does not accept bets, does not form a prize fund, and does not pay out winnings. Poker simulators are meant for training and variance analysis, not for playing for money.
Where does randomness come from?
All number generators, coins, dice, wheels, and selections use the browser's cryptographic generator — crypto.getRandomValues. The values are not "pseudo-random by time": the entropy source is provided by the operating system. Server-side calculations (draw secrets) use random_bytes() in PHP.
Is it possible to rig the draw?
The "Giveaway" tool uses a commit-reveal scheme: before the start, a SHA-256 hash of the secret is published, and afterwards — the secret itself. Winners are calculated from the secret and the list of participants, so the organizer cannot surreptitiously change the result, and any participant can recalculate it on the verification page.
Is registration required and is my data saved?
No registration. Generators work directly in the browser: participant lists and results are not sent anywhere and are not saved on the server. The history of the latest results is stored only in your browser (localStorage) and can be cleared with one button.
Do the tools work without the internet?
Yes, all random number generators, coin flips, dice, wheels, selections, passwords, and colors are computed locally and work offline. Network access is only needed for server poker simulations on large volumes.
Can a generator be used for a prize draw?
Yes, as a tool for random selection. The organizer is independently responsible for complying with the legislation of the Russian Federation: separate regulations apply to promotional activities and lotteries (in particular, Federal Law No. 138-FZ "On Lotteries" and Federal Law No. 38-FZ "On Advertising"). The site does not conduct lotteries and is not their organizer.

Need a random result right now?

One click — and a number, a coin flip or a winner is ready. Free of charge.

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