Don't like ads? Go Ad-Free Today 

ULID Generator

DeveloperRandomSecurity

Generate time-sortable, unique identifiers with our free ULID Generator. Create single or bulk ULIDs in Text, JSON, or YAML format instantly.

ADVERTISEMENT · REMOVE?

INPUT

OUTPUT

Client Side

ADVERTISEMENT · REMOVE?

Guide

What is ULID?

ULID (Universally Unique Lexicographically Sortable Identifier) is a unique identifier format that combines a timestamp with random bits to create time-sortable, unique IDs. Unlike UUIDs, ULIDs are:

Lexicographically sortable by time
Case-insensitive
Crockford’s Base32 encoded
26 characters in length

Key Features

Feature	Description
Time-based Sorting	First 10 characters encode timestamp
Randomness	Last 16 characters ensure uniqueness
Format Options	Generate in Text, JSON, or YAML format
Bulk Generation	Create multiple ULIDs at once

Technical Specifications

Component	Details
Length	26 characters
Timestamp	First 10 characters (48 bits)
Randomness	Last 16 characters (80 bits)
Character Set	Crockford’s Base32 (0-9, A-Z excluding I, L, O, U)

How to Use

Enter the number of ULIDs you want to generate in the “Total” field
Select your preferred output format (Text, JSON, or YAML)
Click the “Generate” button
Copy the generated ULID(s) using the copy button
Reset the form using the “Reset” button if needed

 FAQ

What is a ULID and how is it different from UUID?

A ULID (Universally Unique Lexicographically Sortable Identifier) is a 26-character identifier that combines timestamp and randomness. Unlike UUIDs, ULIDs are sortable by time and use Crockford's Base32 encoding for better readability.
Are ULIDs case-sensitive?

No, ULIDs are case-insensitive. They can be generated and compared in any case, though they're typically displayed in uppercase.
How many ULIDs can be generated per millisecond?

ULIDs can generate about 1.21e+24 unique identifiers per millisecond, making collision extremely unlikely in most applications.
Can ULIDs be used as database primary keys?

Yes, ULIDs make excellent database primary keys because they're unique, sortable, and their timestamp component enables natural chronological ordering.
What's the timestamp format in a ULID?

The first 10 characters of a ULID encode a millisecond-precision timestamp using Crockford's Base32 encoding.
Are ULIDs suitable for distributed systems?

Yes, ULIDs are well-suited for distributed systems because they can be generated without coordination between nodes while maintaining uniqueness and time-sortability.
How do I decode the timestamp from a ULID?

The timestamp can be extracted from the first 10 characters of a ULID by converting from Crockford's Base32 back to milliseconds since Unix epoch.
Is ULID better than UUID for web applications?

ULIDs can be better for web applications that need time-sortable IDs or human-readable identifiers, while maintaining the uniqueness guarantees of UUIDs.