Generate v4 (random) or v7 (time-ordered)? UUIDs? in bulk using your browser's built-in crypto API?. Copy per-row or grab all at once. Nothing leaves your machine.
Sometimes you need reference codes that are guaranteed never to repeat — for spreadsheet rows, file names, order numbers, or test data. Each code this page makes is so random that the chance of two ever matching is effectively zero, so you can hand them out without checking against a list.
Pick how many you need, click Generate, and copy them individually or all at once. They're created right in your browser and never sent anywhere.