By Updated

Nano ID Generator

Generate compact URL-safe Nano IDs with configurable length and custom alphabet, with bulk output

Interactive tool

Nano ID options

Alphabet

What is a Nano ID Generator?

Nano ID is a compact, URL-safe identifier built for the modern web. It is shorter than UUID v4 (21 vs 36 characters by default) while offering comparable collision resistance, and the alphabet is restricted to URL-safe characters out of the box.

How to Use This Nano ID Generator

  1. 1Pick the desired length (default 21)
  2. 2Choose a preset alphabet or enter a custom one
  3. 3Set the count for bulk generation
  4. 4Click regenerate to refresh, then copy or download
  5. 5Paste the IDs into your code, database seeds, or fixtures
What you get

Key features

Compact and URL-Safe

Default 21-character output is shorter than UUID v4 while remaining safe in URLs and filenames

Cryptographically Secure

Uses crypto.getRandomValues for unbiased randomness suitable for security-sensitive use

Custom Alphabet

Override the default alphabet with hex, base32, numbers only, or any character set you need

Length Control

Choose any length from 4 to 64 characters, balancing brevity and collision resistance

Preset Alphabets

One-click presets for hex, alphanumeric, numbers only, and a no-look-alike charset

Bulk Generation

Generate up to 100 IDs at once for batches of database seeds or test data

Entropy Indicator

Total entropy in bits is calculated so you can confirm collision resistance fits your use

100% Private

Generation runs in your browser. Nothing is uploaded

Why Use Nano ID Instead of UUID?

Nano IDs are roughly half the length of UUIDs while offering similar collision resistance. They look cleaner in URLs, take less storage in databases, and stay URL-safe by default. Use UUID when you need a standardized format; use Nano ID when you want a compact, modern identifier with a custom alphabet option.

Common use cases

  • Generating short, URL-safe public IDs for database records
  • Creating short links and shareable resource identifiers
  • Producing test data IDs in fixtures and seeds
  • Generating filenames for uploaded assets
  • Creating session or correlation IDs for distributed tracing
  • Producing product SKUs, coupon codes, or invitation codes
  • Generating numeric-only IDs for legacy systems
  • Creating compact IDs that fit in tight UI spaces

Length and Collision Resistance

A 21-character Nano ID using the default 64-character alphabet has roughly 126 bits of entropy, enough to make collisions practically impossible until you hit billions of IDs per second. Smaller alphabets and shorter lengths reduce entropy, so adjust deliberately.

When to Pick a Custom Alphabet

Use the no-look-alike preset when humans need to read or transcribe IDs. Use hex when you need to express the ID as a number or compare to existing UUIDs visually. Use numbers only for printer-friendly codes. Otherwise, the default URL-safe alphabet is the right call.

Pro tips

Tips & best practices

Stick with the default for most cases

The default 21-character URL-safe alphabet covers nearly every public ID use. Customize only when you have a real reason

Use the no-look-alike preset for printed codes

Drops similar characters like 0/O and l/I/1 so people can read or type IDs without confusion

Watch the entropy indicator

Aim for 80+ bits for general use, 128+ when collisions would be catastrophic

Pair with a timestamp for sortable IDs

Prepend a base36 timestamp to make IDs roughly sortable while keeping the random suffix unique

Avoid super-short IDs at scale

Below 10 characters, collision risk grows fast. Add length before adding complexity

Built for trust

Privacy & security

This Nano ID generator runs entirely in your web browser using the nanoid library and the Web Crypto API. IDs are never uploaded to any server, stored anywhere, or transmitted. All generation happens locally on your device.

Frequently Asked Questions

How is Nano ID different from UUID?

Nano ID produces shorter IDs (21 characters by default vs 36 for UUID) and uses a URL-safe alphabet. Both are random and have similar collision resistance. Use UUID for standards compliance, Nano ID for compactness.

Are Nano IDs cryptographically secure?

Yes. Nano IDs are generated with the Web Crypto API (crypto.getRandomValues), the same source browsers use for security primitives.

What length should I use?

The default 21 characters provides about 126 bits of entropy and is appropriate for nearly all use cases. Increase length when you need more entropy or use a smaller alphabet.

Can I use a custom alphabet?

Yes. Provide any string of at least 2 unique characters. Common presets include hex, alphanumeric, numbers only, and a no-look-alike charset.

Why use the no-look-alike alphabet?

It drops visually similar characters (0/O, l/I/1) so users can read and transcribe IDs without confusion. Useful for printed coupons, badge codes, and customer-facing IDs.

Is my data sent to a server?

No. Generation runs entirely in your browser using the nanoid library. IDs are never uploaded, stored, or transmitted to any server.