Developer / IDs
Nano ID Generator
Generate random, URL-safe IDs like Nano ID with any alphabet and length, many at once, and see how long it takes before a collision becomes likely.
Nano ID Generator: Each character is drawn from the browser's secure random generator and mapped onto the alphabet with a bitmask, rejecting values that fall outside it, the method the nanoid library uses so every character is equally likely. The default, 21 characters of 64, is about as collision-resistant as a UUID v4 in a shorter, URL-safe form. The estimate uses the birthday bound for a 1% chance of any two IDs matching. Runs 100% locally in your browser with zero server file uploads.
- Category
- Developer tools
- Runs
- In your browser
- Cost
- Free · no sign-up
- Availability
- Ready to use
Runs entirely in your browser
At 1,000 IDs an hour, about 149,000,000,000 years pass before a 1% chance of any two being the same.
Characters come from your browser's secure random generator, spread evenly over the alphabet by masking and rejection, as the nanoid library does.
Choosing a length
Each extra character multiplies the possibilities by the alphabet size: with 64 characters, 10 characters give about a billion billion IDs, enough for a small app, and 21 characters match a UUID. Shorter IDs are fine for short-lived or low-volume uses, such as share links.
For standard UUIDs, use the UUID generator; for secrets, the password generator.
IDs are not secrets
Random IDs are hard to guess, but they appear in URLs, logs, and browser history; never use an ID alone as proof of access to private data.
How to use it
- Choose an alphabet, such as URL-safe or digits only, or type your own.
- Set the length and how many IDs to make.
- Copy the IDs; set how many you make per hour to see the collision estimate.
Privacy & limitations
IDs are made in your browser.
Related tools
Frequently asked questions
Nano ID or UUID?
Both are random; Nano ID packs similar randomness into 21 URL-safe characters instead of 36. Use UUIDs where a database or standard expects them.
Can I use a short ID?
Yes, if you make few of them; check the collision estimate, and check new IDs against existing ones if a duplicate would cause trouble.
Why avoid look-alike characters?
For IDs that people read or type, such as order or voucher codes, leaving out 0, O, 1, l, and I prevents misreadings.
Free tool · runs in your browser · no account required