Nano ID Generator
Generate compact, URL-safe Nano IDs with custom length and alphabet. Cryptographically random, unbiased, bulk output. Copy or download — free.
About the Nano ID Generator
This Nano ID generator creates short, URL-safe unique identifiers using the same algorithm as the popular nanoid library. Set how many IDs you need, the length and the alphabet, and get a batch of collision-resistant IDs ready to copy or download — perfect for database keys, short links and public-facing identifiers.
IDs are generated with crypto.getRandomValues and an unbiased mask-and-reject sampling method, so every character is equally likely and the output is cryptographically random rather than merely pseudo-random. The default 21-character URL-safe alphabet gives a collision resistance comparable to a UUID but in a more compact, link-friendly string.
Choose from preset alphabets — URL-safe, alphanumeric, lowercase, hexadecimal, or a no-lookalike set that removes easily confused characters — or supply your own. The tool shows the approximate entropy in bits for your settings so you can judge collision risk. Everything runs locally in your browser.
How to Use the Nano ID Generator
- 1Set how many IDs to generate and the length (default 21).
- 2Pick a preset alphabet or choose Custom to supply your own characters.
- 3Click Generate Nano IDs.
- 4Copy the list or download it as a .txt file.
Frequently Asked Questions
How is a Nano ID different from a UUID?
Both give practically unique identifiers, but a Nano ID is more compact and URL-safe. A default 21-character Nano ID has similar collision resistance to a 36-character UUID while being shorter and free of hyphens, which makes it nicer in URLs and easier to read.
Are these IDs cryptographically secure?
The randomness comes from crypto.getRandomValues, the browser's secure random source, and the tool uses unbiased rejection sampling so no character is favoured. That makes the IDs unpredictable — suitable for tokens and public identifiers, though not a replacement for a signed secret.
What length should I choose?
21 characters (the nanoid default) is a safe general-purpose choice. Shorter IDs are prettier but raise collision odds as you generate more of them; the tool shows the approximate bits of entropy so you can balance length against volume. For high-volume systems, keep the default or go longer.
What does the no-lookalike alphabet do?
It removes characters that are easy to confuse when read or typed by hand — like 0/O and 1/l/I. Use it for IDs people might read aloud, copy manually or enter from a printout, such as coupon or reference codes.
Is anything sent to a server?
No. All ID generation happens in your browser using the local crypto API, so the identifiers are never transmitted or logged anywhere.