Nano ID is a tiny, URL-safe unique-ID format. By default it is 21 characters from a 64-symbol alphabet, giving collision odds comparable to a UUID v4 in a more compact, copy-friendly string.

How does the random selection avoid bias?

This generator uses rejection sampling over the alphabet — the same approach as the reference nanoid library — so every character is equally likely with no modulo bias, drawn from the browser's Web Crypto random source.

Is anything uploaded when I generate IDs?

No. The random bytes and the IDs are produced entirely in your browser, and nothing is uploaded — your custom alphabet never leaves your device.

Nano ID Generator — Gera Tools

Custom Nano ID generator

Nano ID is a tiny, URL-safe unique-ID format. The default is 21 characters drawn from a 64-symbol alphabet, which gives collision resistance comparable to a UUID v4 in a shorter, copy-friendly string with no hyphens.

This generator uses rejection sampling over your chosen alphabet — the same unbiased technique as the reference library — backed by the browser’s cryptographic random source. Set any length, swap in a custom alphabet, and mint a single ID or a batch of up to a thousand. Everything runs entirely in your browser, nothing is uploaded.