ToolHub
Open Tool

ULID Generator

Generate sortable ULID unique identifiers

Developer Tools
Launch Tool All Tools

About This Tool

The ULID Generator creates Universally Unique Lexicographically Sortable Identifiers that combine a 48-bit timestamp with an 80-bit random component. ULIDs are URL-safe, sortable by time, and use Crockford's Base32 encoding. All generation happens locally in your browser using the Web Crypto API for secure randomness.

Key Features

Quick Preview

Use Cases

id generator

Frequently Asked Questions

What is the ULID Generator?

The ULID Generator is an online developer tool that generates sortable ULID unique identifiers. It runs entirely in your browser with no data sent to any server.

What is the difference between ULID and UUID?

ULIDs are 26-character strings using Crockford's Base32 encoding, while UUIDs are 36-character hex strings with hyphens. ULIDs are lexicographically sortable by creation time, making them ideal for database indexing. UUIDs are random and not sortable.

What timestamp precision does ULID use?

ULID uses a 48-bit Unix timestamp with millisecond precision. The timestamp occupies the first 10 characters of the ULID, providing time-ordered uniqueness. Two ULIDs created in the same millisecond are differentiated by the 80-bit random component.

How many ULIDs can I generate at once?

You can generate between 1 and 20 ULIDs at once using the count selector. Each ULID is generated independently with its own timestamp and random component, ensuring all are unique.

Is ULID URL-safe?

Yes. ULIDs use Crockford's Base32 encoding which only contains uppercase letters and digits (0-9, A-Z, excluding I, L, O, U to avoid ambiguity). This makes them safe to use in URLs without any encoding.