UUID Generator
Generate universally unique identifiers (v4 UUIDs). Create multiple UUIDs at once and copy them with a single click.
How to Use
- Choose how many UUIDs to generate (1 to 100).
- Click "Generate UUIDs" to create them.
- Click the copy button next to any UUID to copy it individually.
- Use "Copy All" to copy every UUID at once, one per line.
Features
- Generates standard RFC 4122 version 4 UUIDs
- Create 1 to 100 UUIDs at a time
- Copy individual UUIDs or all at once
- Displays a running count of generated UUIDs
- Uses cryptographically secure random values
- Works entirely in your browser - no data sent to servers
- Mobile-friendly responsive interface
Why Use a UUID Generator
Universally Unique Identifiers, or UUIDs, are 128-bit values used to identify resources without requiring a central authority or coordination between systems. They are widely used in software development, database design, and distributed systems where records need unique identifiers that will not collide, even when generated independently across different machines and time zones.
Developers frequently need UUIDs when building APIs, designing database schemas, or setting up test data. Instead of relying on auto-incrementing integers that can reveal information about record counts or creation order, UUIDs provide opaque identifiers that are safe to expose in URLs and public interfaces. Version 4 UUIDs, which this tool generates, are based entirely on random values, making them unpredictable and suitable for most identification needs.
This tool lets you generate up to 100 UUIDs at once, which is especially convenient when you need to populate a database seed file, configure multiple test resources, or prepare identifiers for a batch import. Every UUID is generated using the browser's cryptographically secure random number generator, ensuring high-quality randomness. You can copy individual UUIDs or all of them at once with a single click, saving you the effort of writing a script just to produce a handful of identifiers.
Frequently Asked Questions
What is a UUID and what does v4 mean?
A UUID (Universally Unique Identifier) is a 128-bit identifier formatted as 32 hexadecimal digits separated by hyphens, such as 550e8400-e29b-41d4-a716-446655440000. Version 4 (v4) means the UUID is generated using random or pseudorandom numbers rather than being derived from a timestamp or hardware address, making it the most commonly used version in modern applications.
Can two UUIDs ever be the same?
While theoretically possible, the probability of generating two identical v4 UUIDs is astronomically low. With 122 random bits, there are over 5.3 undecillion possible combinations. You would need to generate about 2.7 quintillion UUIDs before having a 50% chance of a single collision. For all practical purposes, every UUID you generate will be unique.
Where are UUIDs commonly used?
UUIDs are used as primary keys in databases, as identifiers in REST APIs, for tracking distributed transactions, as filenames for uploaded content, and in messaging systems to correlate requests. They are especially popular in microservice architectures where multiple services need to create identifiers independently without a shared counter.
Are UUIDs safe to use in URLs?
Yes, UUIDs consist of hexadecimal characters and hyphens, all of which are URL-safe. They are commonly used in URL paths and query parameters. Because v4 UUIDs are random, they do not reveal any information about creation time, order, or record count, making them a more secure choice than sequential integer IDs for public-facing URLs.