NanoID Generator
Generate compact, URL-safe NanoIDs with Web Crypto. Choose count and size, optionally set a custom alphabet, then copy one or all. Everything runs in your browser — nothing is sent to a server.
NanoID generator controls
How it works
NanoID produces compact random strings from a configurable alphabet. By default it uses the
URL-safe set A–Z a–z 0–9 _ - (64 symbols) at length 21, which offers strong collision
resistance while staying shorter than a classic UUID string.
Set how many IDs to create, the size (8–64), and optionally a custom alphabet. Random bytes come from Web Crypto; biased sampling is avoided so each alphabet symbol stays evenly likely.
Unlike ULID or UUID v7, NanoIDs here carry no embedded timestamp — they are opaque random tokens suited to public URLs and short references.
When to use this tool
- Short public IDs for links, invite codes, or file names
- Custom alphabets (for example digits-only or no look-alike characters)
- When you do not need time-sortable IDs (use ULID or UUID v7 for that)
- Bulk sample tokens for tests without installing the NanoID library locally
Tips
- Shorter sizes raise collision risk — keep production IDs long enough for your volume
- Leave the alphabet blank to use the URL-safe default
- Duplicate symbols in a custom alphabet are fine; entropy still depends on unique symbol count and length
Frequently asked questions
What is a NanoID?
A NanoID is a compact, URL-safe unique string ID. The default alphabet is A-Za-z0-9_- (64 characters) and the default length is 21, which gives collision resistance comparable to UUID v4 while producing shorter, prettier IDs for URLs and public tokens.
NanoID vs UUID / ULID?
UUID (including v7) is a fixed 128-bit standard with hex formatting. ULID is 26 Crockford Base32 characters and embeds a timestamp so IDs sort by time. NanoID is fully random (no timestamp), customizable in length and alphabet, and typically shorter for the same collision resistance when using the URL-safe alphabet.
Does my NanoID data leave my browser?
No. Generation runs entirely in your browser with JavaScript and Web Crypto. Nothing is uploaded to a server.
Is this NanoID generator free?
Yes. The Formattly NanoID Generator is free to use with no signup required.
What size should I choose?
The default size of 21 with the URL-safe alphabet is a solid general-purpose choice. Use longer IDs for very high issuance rates, or shorter ones only when collisions are acceptable (for example throwaway demo labels).