UUID Generator

Generate UUIDs instantly in your browser. Create v1, v4, or nil UUIDs in bulk for databases, APIs, and distributed systems. Free, no signup required.

How to Generate UUIDs Online

  1. 1

    Select the UUID version

    Choose the UUID version you need. Version 4 (random) is the most common choice for general-purpose unique identifiers. Version 1 (time-based) is useful when you need identifiers that encode a timestamp.
  2. 2

    Set the quantity and format

    Enter how many UUIDs you need (up to 100 at once for bulk generation). Choose uppercase or lowercase and whether to include hyphens.
  3. 3

    Generate your UUIDs

    Click the Generate button to create your UUIDs instantly. All generation happens in your browser using the Web Crypto API, so nothing is sent to a server.
  4. 4

    Copy and use

    Click Copy to grab a single UUID, or use Copy All to get the entire batch. Paste them into your database schema, API code, configuration file, or test data.

Common Use Cases

1

Database Primary Keys

UUIDs are widely used as primary keys in relational and NoSQL databases. Unlike auto-increment integers, UUIDs can be generated on any client or server without coordination, making them ideal for distributed databases and multi-region architectures.
2

API Request Identifiers

Assign a unique UUID to every API request for end-to-end tracing. Correlation IDs help you track a request across microservices, search logs quickly, and debug production issues without ambiguity.
3

Session Tokens and Nonces

UUID v4 values generated from a cryptographically secure random source make strong session tokens, CSRF nonces, and one-time-use codes. Their 122 bits of entropy make brute-force attacks computationally infeasible.
4

Distributed Systems and Event Sourcing

In event-driven architectures, every event, message, or job needs a globally unique identifier. UUIDs let each node generate IDs independently with virtually zero collision risk, removing the bottleneck of a central ID service.

Why use UUIDs?

UUIDs (Universally Unique Identifiers) provide a way to generate unique identifiers without a central authority. They're essential for distributed systems, databases, and APIs where you need guaranteed uniqueness across systems and time.

A UUID (Universally Unique Identifier) is a 128-bit value standardized by RFC 4122 and its successor RFC 9562. UUIDs provide a reliable way to create identifiers that are unique across space and time without requiring a central registration authority. This makes them the default choice for primary keys, correlation IDs, and object references in modern software.

The most common versions are UUID v1 (time-based), UUID v4 (random), and the newer UUID v7 (time-ordered random). Version 1 encodes the current timestamp and a node ID, which guarantees uniqueness but can reveal when and where the ID was created. Version 4 fills 122 of the 128 bits with cryptographically random data, making collisions practically impossible while revealing nothing about the source. Version 7, introduced in RFC 9562 (2024), combines a Unix-epoch millisecond timestamp with random bits, giving you both chronological ordering and strong uniqueness -- ideal for database primary keys that need efficient B-tree indexing.

This UUID generator runs entirely in your browser using the Web Crypto API. No data is transmitted to any server, so your generated IDs remain private. You can create UUIDs in bulk, switch between uppercase and lowercase formats, and remove hyphens for systems that require a compact 32-character string. If you also need deterministic hashes for data verification, check out the SHA-256 Hash Generator or the MD5 Hash Generator.

How It Compares

Unlike server-side UUID generators such as uuidgenerator.net, this tool creates UUIDs entirely in your browser. Nothing is uploaded or logged, so your identifiers stay private. You can generate up to 100 UUIDs at once with one click, choose between v1 and v4, toggle hyphens and casing, and copy the full batch instantly. There is no signup, no rate limit, and no ads -- just a fast, free UUID generator you can bookmark and use whenever you need it.

UUID Tips & Best Practices

1
Use UUID v4 for most applications. Its 122 random bits are generated from a cryptographically secure source and work well as database keys, object IDs, and tokens.
2
UUID v1 embeds a timestamp and a node identifier (usually derived from the MAC address). Avoid v1 in public-facing contexts if you do not want to leak timing or hardware information.
3
UUID v7 (RFC 9562, 2024) is a newer time-ordered format designed specifically for database indexing. It preserves chronological sort order while keeping strong randomness, making it more efficient than v4 for B-tree indexes.
4
Storing UUIDs as 16-byte binary (BINARY(16) in MySQL, uuid type in PostgreSQL) instead of a 36-character string saves storage and improves index performance by up to 50%.
5
The probability of a collision among UUID v4 values is approximately 1 in 2^122. You would need to generate about 2.7 quintillion UUIDs to have a 50% chance of a single duplicate.

Frequently Asked Questions

1

What is a UUID?

UUID (Universally Unique Identifier) is a 128-bit identifier that's practically guaranteed to be unique. It's commonly used in databases, distributed systems, and software development to identify objects.
2

What's the difference between UUID versions?

UUID v1 uses timestamp and MAC address, v4 is random (most common), v5 uses namespace and SHA-1 hashing. Each version has different use cases and uniqueness guarantees.
3

Are UUIDs truly unique?

UUIDv4 has 122 random bits, making collisions astronomically unlikely (1 in 5.3x10^36). For practical purposes, you can generate billions of UUIDs without worrying about duplicates.
4

What's the difference between UUID and GUID?

UUID and GUID are essentially the same thing. GUID (Globally Unique Identifier) is Microsoft's term for UUID. They follow the same format and can be used interchangeably.
5

Can I generate UUIDs without hyphens?

Yes! Our tool allows you to copy UUIDs with or without hyphens. The 32-character format without hyphens is useful for certain systems that don't accept special characters.

Related Tools

Password Generator

Security

Random Key Generator

Security

Md5 Hash Generator

Security

Sha256 Hash Generator

Security

Base64 Encoder

Developers

Unix Timestamp

Developers

Cron Expression Generator

Developers

Hash Comparison Tool

Security

Related Guides

UUID Generator Guide: UUID Versions Explained (v1, v4, v7) with Code Examples 10 min read

Rate This Tool

0/1000

Get Weekly Tools

Suggest a Tool