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CUID Generator

Generate secure, collision-resistant IDs optimized for horizontal scaling and performance. All IDs are generated locally in your browser—nothing is sent to our servers.

Why Use Utiliti's CUID Generator?

CUIDs are often used in production systems where ID predictability could be a security concern. Unlike many online ID generators that process requests server-side, Utiliti's CUID Generator runs entirely in your browser.

Your generated IDs never leave your device, making it safe to:

  • Test ID Formats: Experiment with CUID lengths without exposing your ID patterns
  • Generate Production IDs: Create IDs for sensitive systems without third-party logging
  • Batch Generation: Generate hundreds of IDs privately for testing or seeding databases

Features

  • Adjustable Length: Generate CUIDs from 5 to 50 characters to fit your requirements
  • Batch Generation: Create up to 500 CUIDs at once
  • Instant Output: IDs are generated immediately with no server round-trip
  • One-Click Copy: Easily copy all generated IDs to your clipboard

How to Use

  1. Set the length: Adjust the length slider to your desired ID length (default is 24 characters)
  2. Set the quantity: Choose how many CUIDs you need (1-500)
  3. Copy the output: Click the copy button to grab your generated IDs

What is CUID?

CUID (Collision-resistant Unique Identifier) is a modern ID generation algorithm designed for distributed systems. CUID2 (the version used here) is the latest iteration, offering improved security and randomness over the original CUID.

Key characteristics of CUID2:

  • Collision Resistant: Designed to be unique across distributed systems without coordination
  • Secure: Uses cryptographically secure random number generation
  • Horizontal Scaling: Safe to generate across multiple servers simultaneously
  • URL Safe: Contains only lowercase letters and numbers
  • Non-Sequential: IDs don't reveal creation order, improving security

CUID vs UUID

While both CUID and UUID solve the unique identifier problem, they have different characteristics:

  • Length: CUIDs are variable length (default 24 chars) vs UUIDs fixed 36 characters
  • Characters: CUIDs use only lowercase alphanumeric vs UUIDs use hex with dashes
  • Security: CUID2 is designed to be non-guessable; UUIDv4 is random but UUIDv1 leaks timestamp/MAC
  • Size: CUIDs can be shorter, saving storage in high-volume systems

Common Use Cases

  • Database Primary Keys: Ideal for distributed databases where auto-increment isn't practical
  • API Resource IDs: URL-safe format works perfectly in REST endpoints
  • Session Identifiers: Secure, non-guessable IDs for user sessions
  • File Names: Generate unique, URL-safe file names for uploads
  • Microservices: Generate IDs across services without central coordination

Learn More

CUID2 was created by Eric Elliott. For technical details and the full specification, visit the official CUID2 repository on GitHub.

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