Random ID Generator
Generate random IDs, reference codes and short tokens with the characters and length you choose, plus an estimate of how many you can make before two might match.
About this tool
Choose the characters, the length and how many you need. Every character is picked by your browser’s cryptographic random generator with no bias towards any letter, and each batch contains no duplicates. The URL-safe set matches the popular nanoid format, so a 21-character ID is as hard to guess as a UUID. The no-look-alikes set (Crockford’s Base32) is best for codes people read aloud or type in, such as booking references.
The estimate under the list uses the birthday problem: with random IDs, the chance of a repeat grows much faster than people expect, so it tells you how many IDs you could create in total before there’s a 1% chance of any two matching. If that number is close to how many you’ll ever need, make the IDs longer. For security tokens, aim for at least 128 bits. Your settings are remembered on this device.