CUID2 is the second generation of the Collision-Resistant Unique Identifier. It uses cryptographically strong randomness and starts with a lowercase letter, producing short, URL-safe IDs ideal for database primary keys and distributed systems.

How likely is a collision?

With a length of 10 characters using a 36-character alphabet, you would need to generate billions of IDs before a collision becomes remotely probable. The tool shows the exact mathematical probability for your settings.

Can I use these as database primary keys?

Yes. CUID2 was specifically designed for use as collision-resistant identifiers in databases and distributed systems. The configurable length lets you balance key size against collision safety.

CUID2 Generator

Generate CUID2 identifiers with configurable length, batch output, and real-time collision probability estimates.

import CopyButton from "./_CopyButton.astro"

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CUID2 Identifiers

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How to use CUID2 Generator

Set your desired ID length (2-32 characters).
Choose how many IDs to generate (1-100).
Click Generate and use the copy buttons to use your CUID2 identifiers.

What is CUID2 Generator?

CUID2 is a collision-resistant identifier format designed to be short, URL-friendly, and highly unlikely to collide. Each ID starts with a lowercase letter followed by alphanumeric characters, making them safe for use in URLs, database keys, and distributed systems.

This browser-based tool lets you customize the ID length from 2 to 32 characters, generate up to 100 IDs at once, and see the mathematical collision probability for your chosen parameters. All generation uses crypto.getRandomValues for strong randomness.

FAQ

What is CUID2?: CUID2 is the second generation of the Collision-Resistant Unique Identifier. It uses cryptographically strong randomness and starts with a lowercase letter, producing short, URL-safe IDs ideal for database primary keys and distributed systems.
How likely is a collision?: With a length of 10 characters using a 36-character alphabet, you would need to generate billions of IDs before a collision becomes remotely probable. The tool shows the exact mathematical probability for your settings.
Can I use these as database primary keys?: Yes. CUID2 was specifically designed for use as collision-resistant identifiers in databases and distributed systems. The configurable length lets you balance key size against collision safety.

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CUID2 Generator

How to use CUID2 Generator

What is CUID2 Generator?

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