UUID Generator

Generate unique identifiers (UUIDs)

Count

Format

Free Online UUID Generator

Our free UUID generator creates universally unique identifiers (UUIDs) instantly in your browser. Generate one or up to 100 version-4 UUIDs at a time in standard, simple (no hyphens), or uppercase format. Whether you are a developer seeding a database, a QA engineer generating test data, or a system architect designing distributed services, this tool delivers the unique IDs you need in seconds.

A UUID (Universally Unique Identifier) is a 128-bit value standardized by RFC 4122 that is designed to be unique across space and time without requiring a central registration authority. Version 4 UUIDs, which this tool generates, use random or pseudo-random numbers and are the most widely adopted variant in modern software development.

All generation happens entirely client-side using JavaScript, so your data never touches a server. Copy a single UUID with one click, or copy all generated UUIDs at once to paste into your codebase, configuration file, or spreadsheet.

Key Features

Generate 1 to 100 UUIDs in a single batch
Three output formats: standard (with hyphens), simple (no hyphens), and uppercase
RFC 4122 compliant version-4 UUID generation
One-click copy for individual UUIDs
Copy All button to grab every UUID at once
Clean monospace display for easy reading
Instant generation with no loading delay
Fully client-side — no server requests, no data stored
Works on desktop, tablet, and mobile browsers
No account, sign-up, or payment required

How to Use the UUID Generator

Set the count: Enter how many UUIDs you need (from 1 up to 100).
Choose a format: Select Standard (e.g., 550e8400-e29b-41d4-a716-446655440000), Simple (no hyphens), or Uppercase.
Click Generate: Press the Generate button to create your UUIDs instantly.
Copy individual UUIDs: Click the copy icon next to any single UUID to copy it to your clipboard.
Copy all at once: Use the "Copy All" button to copy every UUID separated by newlines.

Use Cases

Database primary keys: Use UUIDs as primary keys in relational and NoSQL databases to avoid collisions across distributed systems.
API request IDs: Attach a UUID to each API request for end-to-end tracing and debugging in microservice architectures.
Session tokens: Generate unique session identifiers for web application authentication and user tracking.
File naming: Assign UUIDs as file names to prevent overwrites when storing user uploads.
Test data generation: Quickly generate batches of unique IDs to populate test databases and mock environments.
Distributed systems: Ensure globally unique object identifiers without a central coordination service.
Configuration keys: Create unique identifiers for feature flags, experiment IDs, or deployment versions.

Frequently Asked Questions

Is this tool free?

Yes, the UUID generator is completely free with no limits on the number of UUIDs you can create. No account is required.

Is my data secure?

All UUID generation happens locally in your browser. No data is sent to any server, and nothing is stored or logged.

Are these UUIDs truly unique?

Version 4 UUIDs use 122 bits of randomness, producing over 5.3 x 10^36 possible values. The probability of a collision is astronomically low for practical purposes.

What is the difference between standard and simple format?

Standard format includes hyphens (e.g., 550e8400-e29b-41d4-a716-446655440000) while simple format removes the hyphens for a continuous 32-character hexadecimal string.

Can I use these UUIDs in production?

Yes, the generated UUIDs follow the RFC 4122 v4 specification and are suitable for production databases, APIs, and distributed systems.

Are these cryptographically secure?

This generator uses Math.random() which is suitable for identifiers but not for security-sensitive applications like encryption keys. For cryptographic use, consider crypto.getRandomValues().

Tips & Best Practices

Use standard format for readability: The hyphenated format is easier to read and debug in logs and database queries.
Use simple format for URLs: Remove hyphens when embedding UUIDs in URLs or file paths to keep them compact.
Index UUID columns properly: In databases, use binary storage (BINARY(16)) instead of VARCHAR for better performance.
Batch generate for testing: Use the count feature to generate up to 100 UUIDs at once for test data seeding.
Avoid sequential patterns: Version 4 UUIDs are random by design, which is ideal for preventing enumeration attacks on public-facing IDs.