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Nano ID Generator

Generate short, unique, URL-safe IDs in 21 characters. 126 bits of entropy. Faster and smaller than UUID.

URL-Safe 126-bit Entropy 21 Characters No Hyphens
IDs
Output

Why Nano ID?

UUID is 36 characters with hyphens. Nano ID is 21 characters without hyphens. For modern web applications, that difference compounds:

  • URLs: Shorter IDs = shorter URLs = better for sharing, easier to type, better for QR codes.
  • Databases: 21-character strings are smaller than 36-character UUIDs, reducing index size and improving cache hits.
  • APIs: Less data transmitted per request. Across millions of requests, this adds up.
  • Frontend: Shorter IDs in state objects, LocalStorage, URLs — less memory and storage.

Nano ID vs UUID

Property UUID v4 UUID v7 Nano ID
Format 8-4-4-4-12 hex 8-4-4-4-12 hex 21 URL-safe chars
Length 36 characters 36 characters 21 characters
Entropy 122 bits 80 bits 126 bits
Sortable No Yes No
Alphabet 0-9, a-f (hex) 0-9, a-f (hex) 0-9, a-z, A-Z, -, _ (base62)
RFC 4122 Compliant Yes Yes No (proprietary)

Use Cases

URL Slugs & Sharing

Instead of: example.com/documents/550e8400-e29b-41d4-a716-446655440000

You get: example.com/documents/V-st_DuCn2b1vQwxmzA89

Shorter URLs rank slightly better in search, are easier to share, and look cleaner in user-facing links.

Database Primary Keys

Nano ID works as a primary key like UUID. VARCHAR(21) vs VARCHAR(36) saves space. In databases with billions of rows, that difference is significant.

API Request Tracking

Include Nano IDs in request headers and logs. You get the same tracking benefits as UUID but with shorter identifiers in logs and monitoring dashboards.

Short Codes & Invites

Stripe, Vercel, and other modern APIs use Nano IDs (or similar) for customer-facing identifiers. They're short enough to type, long enough to be unique, and no special characters.

Frontend State & URLs

Temporary IDs for UI components, route parameters, temporary tokens — Nano ID keeps everything compact.

Nano ID Alphabet

Nano ID uses this 64-character alphabet by default:

V-st_DuCn2b1vQwxmzA89EFfghjkqyrN0OPp3KIiLaRTc4ZJdGs56

It's URL-safe (no / or + like Base64) and doesn't include confusing characters (no 0 vs O, no 1 vs l, no - vs _). This matters when sharing IDs verbally or in printed documents.

Collision Probability

With 126 bits of entropy, Nano ID has even lower collision risk than UUID v4 (122 bits). Birthday paradox: you need ~2^63 IDs before a 50% collision chance. That's 9.2 quintillion IDs. If you generate 1 billion per second, it's still 290 million years.

When NOT to Use Nano ID

  • Regulated systems: Industries requiring RFC 4122 UUID compliance (healthcare, finance) may mandate UUID.
  • Enterprise/legacy: Systems expecting 36-character hex UUIDs specifically.
  • Sortable IDs: If you need timestamp-based sorting, use UUID v7 instead.
  • Cryptographic purposes: Neither Nano ID nor UUID v4 should be used for security tokens — use crypto.getRandomValues().

Implementation Notes

Nano ID is popular in JavaScript but exists in other languages too:

  • JavaScript/Node: npm install nanoid — official, well-maintained.
  • Python: pip install nanoid — community port.
  • Go: github.com/matoous/go-nanoid — popular Go port.
  • Rust: nanoid crate — official Rust port.
  • Java: Several community ports available.

FAQ

Frequently Asked Questions

What is a Nano ID?

Nano ID is a small, URL-safe string identifier (21 characters). It was created to replace UUID v4 in modern applications. Instead of 36 characters with hyphens (xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx), Nano ID is just 21 URL-safe characters (V-st_DuCn2b1vQwxmzA89). Same security/entropy, shorter and faster to generate.

Is Nano ID as secure as UUID?

Nano ID has 126 bits of entropy vs 122 for UUID v4 — it's actually slightly more random. However, like UUID v4, it's not cryptographically secure for security tokens. For those, use crypto.getRandomValues(). Nano ID is perfect for databases, URLs, and request IDs.

Why use Nano ID instead of UUID?

Size matters: 21 chars vs 36 chars. Nano ID is ~40% shorter, improving: database storage (smaller indexes), URL length (better for SEO/sharing), performance (less data transmitted). For modern applications that don't need RFC 4122 compliance, Nano ID is the better choice. UUID remains important for enterprise/legacy systems.

Can I use Nano ID in a database?

Yes. Store it as VARCHAR(21) or similar. Unlike UUID, which has special database types (UUID in PostgreSQL, BINARY(16) in MySQL), Nano ID is just a string. This makes it simpler in some databases but means you lose some optimization (Nano ID is larger than BINARY(16)).

Is Nano ID standardised?

No formal RFC (unlike UUID). Nano ID was created by Andrey Sitnik and is de facto standard in the JavaScript ecosystem. It's used by Vercel, Stripe, Figma, and many modern startups. For regulated industries or legacy systems, stick with UUID. For new projects, Nano ID is often the better choice.

Can I use Nano ID in URLs?

Yes, that's one of its strengths. Nano ID uses a URL-safe alphabet (no +, /, or = characters). You can safely use it in URLs, slugs, or anywhere a string is needed. UUID with hyphens is also URL-safe, but Nano ID is shorter and doesn't need encoding/decoding.

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The DevTools Team
Infinfy Engineering
We build free developer utilities that we actually use ourselves. No accounts, no tracking, no backend — just fast, accurate, in-browser tools. Part of Infinfy Solutions.