What is the Nano ID Generator?
Nano ID is a popular approach to generating unique identifiers that are shorter than UUIDs and safe to use in URLs. Instead of the 36-character, hyphenated UUID format, a Nano ID is a compact string of random letters and numbers — 21 characters by default — that fits neatly into links, file names and database keys.
This tool lets you set the length anywhere from 4 to 64 characters and create up to 200 IDs at once. Every character is chosen with the Web Crypto API in your browser, so the IDs come from a cryptographically secure random source and are never sent to a server. The default 21-character length gives a collision probability comparable to a random UUID, which is why it is widely used for public IDs.
Shorter IDs are handy for human-facing codes and short links, but the chance of a collision rises quickly as length falls. Longer IDs are virtually collision-free. Choose the length based on how many IDs your system will ever create and whether people need to read or type them.
How to use the Nano ID Generator
- Set the Length of each ID, from 4 to 64 characters (21 is the default).
- Enter How many? IDs you need, up to 200.
- Press Generate to create the IDs.
- Copy a single ID or export the whole list as CSV, JSON or TXT.
Popular uses
- Web developers — create public-facing IDs for URLs instead of exposing database row numbers.
- Backend engineers — generate primary keys and record IDs for seed data.
- QA testers — fill ID fields with valid values of different lengths.
- Product teams — produce short share links, invite codes and slugs.
Why use RandNow?
- Instant & unlimited — no sign-up, no daily caps.
- Private by design — results are generated in your browser, not on our servers.
- Export-ready — copy, CSV, JSON and TXT downloads built in.
- Cryptographically random — powered by the Web Crypto API.
Nano ID vs UUID
A version 4 UUID contains 122 random bits spread over 36 characters including hyphens. A 21-character Nano ID packs similar randomness into a shorter string because each character can represent more values. Both are generated randomly, so neither reveals creation order. If you need IDs that sort by time, consider a ULID instead.
Choosing a length
For IDs that must stay unique across millions of records, keep the default of 21 or go longer. Reserve very short lengths for small, human-readable sets where you check for duplicates. Press Generate again for a fresh set — it’s free and unlimited.
Frequently asked questions
What is a Nano ID?
A Nano ID is a short, URL-safe random identifier — 21 characters by default — used as a compact alternative to UUIDs.
Are Nano IDs unique?
They are random, so uniqueness is probabilistic. At the default 21 characters the chance of a collision is extremely small, similar to a random UUID.
Can I change the ID length?
Yes. Set any length from 4 to 64 characters. Shorter IDs are easier to read but more likely to collide.
How many Nano IDs can I generate at once?
Up to 200 per batch.