Shuffle Lines

In short Shuffling lines reorders a list randomly using a Fisher-Yates shuffle seeded by the browser's cryptographic random source rather than by the ordinary pseudo-random generator. That distinction is the reason to use this rather than a spreadsheet formula. Fisher-Yates is the algorithm that produces every possible ordering with equal probability; the naive alternative — sorting with a random comparison function — is biased, and measurably so, which is a well-known bug that has shipped in real code more than once. Using crypto.getRandomValues rather than Math.random means the sequence is not predictable from previous results, which matters if the shuffle decides anything of value. The uses are drawing an order for a giveaway, randomising question order in a quiz, and creating a randomised sample from a list. One thing worth saying plainly: the shuffle is genuinely random, so it can produce an order that looks unshuffled in places. Runs of consecutive items appear in random orderings more often than intuition suggests, and reshuffling until it looks random enough makes the result less random, not more.