List Randomizer
Shuffle any list into a random order. Paste one item per line.
How It Works
The List Randomiser shuffles any list into a uniformly random order using the Fisher–Yates algorithm seeded by the browser’s crypto.getRandomValues. Paste your list — one item per line — into the input, and click Shuffle to see a fresh random ordering. Each click produces a different permutation, and the algorithm guarantees every one of the n! possible orderings is equally likely (which is the property that off-the-shelf ‘shuffle’ implementations using Math.random and naive sorting fail to provide — a famous pitfall in the algorithm-mistakes literature). Use cases include shuffling a playlist or reading list, randomising the order of presentations or interviews to avoid order bias, generating random seating or team matchups, creating a random presentation order from a list of topics, and educational demonstrations of permutation counting. Empty lines are ignored, and the output preserves the exact text of each item — leading and trailing whitespace is left as-is, since it may be meaningful. Shuffling runs entirely in your browser, so even confidential lists (employee names, candidate identifiers) stay on your device.
Use Cases
- Randomising a playlist or reading list
- Shuffling a deck of cards or a set of flashcards
- Creating random seating arrangements or team matchups
- Generating a random schedule from a list of tasks
Frequently Asked Questions
- Is the shuffle truly random?
- Yes — the Fisher-Yates algorithm with crypto.getRandomValues produces a uniform distribution over all permutations. Every ordering is equally likely.
- Why not sort with Math.random?
- A common but broken pattern: arr.sort(() => Math.random() - 0.5) produces non-uniform results because most sort algorithms make biased comparisons. Fisher-Yates is the correct algorithm.
- How big a list can I shuffle?
- Tens of thousands of items in milliseconds. Beyond that, browser tab responsiveness is the limit.
- Are duplicates kept?
- Yes. The shuffle preserves every input item exactly; it does not deduplicate.
- Is my list sent anywhere?
- No. Shuffling happens entirely in your browser and the input is discarded when you close the tab.