Random Generator

What is a Random Generator?

A random generator creates unpredictable outcomes using cryptographic randomness. Unlike pseudo-random math functions, this tool uses your browser's crypto.getRandomValues() API for true randomness — the same technology used in security systems and encryption.

How Each Mode Works

Random Number: Pick one or more random numbers within any range. Toggle uniqueness to avoid repeats and sort for ordered results. Perfect for raffles, lotteries, and sampling.

Dice Roller: Supports polyhedral dice from d4 to d100. Roll multiple dice at once, see each result, and view the total sum. Ideal for board games, RPGs (D&D), and probability experiments.

Coin Flip: Flip a virtual coin with realistic animation. Track heads/tails statistics over multiple flips to observe probability in action.

Spin the Wheel: Add custom options and spin to pick one at random. Great for team selection, giveaway winners, or just deciding where to eat.

Decision Maker: Stuck between choices? Let randomness decide. Yes/No, True/False, or three-way decisions. Type a question for context.

Who Needs a Random Generator?

• Teachers: Randomly select students, create groups, pick quiz questions
• Gamers: Roll dice for tabletop RPGs, board games, or probability checks
• Content Creators: Pick giveaway winners, randomize video content
• Developers: Generate test data, sample datasets, random IDs
• Everyone: Make fair decisions, settle disputes, add fun to daily life

Where the randomness comes from, and what it is good for

Every draw here comes from crypto.getRandomValues(), the browser's cryptographically secure generator — not Math.random().

• Math.random() is fast and fine for cosmetic jitter (animation offsets, a placeholder colour), but it is not unpredictable: a few observed outputs are enough to reconstruct its internal state, so never use it for tokens, dice in a game with money, or anything security-relevant.
• Unbiased sampling needs care. Mapping a random byte with % n introduces modulo bias whenever the range is not a multiple of n, which makes some outcomes slightly more likely. Rejection sampling removes it.
• Shuffling a list takes Fisher-Yates. Sorting by a random key (sort(() => Math.random() - 0.5)) is biased and slower, and it breaks as soon as the comparator returns 0 for two elements.
• Need to replay a sequence in a bug report? Write the values down. The crypto API cannot be seeded — a seeded PRNG is the only way to reproduce a random sequence exactly.
• crypto.randomUUID() needs a secure context, so it is available on https and on localhost but not on a plain http origin.

Frequently Asked Questions

Is the randomness truly random?

Yes. This tool uses your browser's crypto.getRandomValues() API, which is cryptographically secure. It's the same randomness used for encryption keys and security tokens — far more random than typical Math.random() functions.

Can I use this for giveaways?

Absolutely! Use the Number generator for numbered tickets or the Wheel mode for named entries. The crypto-grade randomness ensures fair results. Copy results easily for documentation.

Is this tool free?

Yes, completely free. No signup, no ads, no limits. All processing happens locally in your browser — nothing is sent to any server.

Can AI do this?

AI language models cannot generate truly random numbers. They produce deterministic outputs based on patterns. For genuine randomness, you need cryptographic tools like this one that access your device's hardware random number generator.

Does the wheel support weighted entries?

Currently the wheel gives equal probability to each entry. Weighted entries are planned for a future update.

What's the maximum range for number generation?

You can generate numbers from -1 billion to +1 billion. For very large ranges, results are uniformly distributed across the full range.

Use Cases

• Giveaways: Pick random winners from ticket numbers or participant names
• Gaming: Roll dice for D&D, Warhammer, or any tabletop game
• Teaching: Random student selection, group assignments, quiz question picking
• Decision Making: Break ties, settle debates, choose randomly between options
• Testing: Generate random test data for development and QA