🎲 UUID Generator

UUID Generator - Generate Random UUIDs and GUIDs Online

The UUID Generator is a free, browser-based tool that creates random Version 4 UUIDs (Universally Unique Identifiers) instantly. Generate one UUID or hundreds at a time, choose from multiple output formats, and copy individual UUIDs or the entire batch with a single click. No installation, no account, and no server calls — everything runs locally in your browser.

What Is a UUID?

A UUID (Universally Unique Identifier), also known as a GUID (Globally Unique Identifier) in Microsoft contexts, is a 128-bit number used to uniquely identify information in computer systems. The standard format is a 32-character hexadecimal string divided into five groups by hyphens: 8-4-4-4-12 characters (e.g., 550e8400-e29b-41d4-a716-446655440000). UUIDs are standardized by RFC 4122 and are widely used across virtually every programming language, database system, and platform.

Version 4 UUIDs, which this tool generates, are created using random or pseudo-random numbers. The probability of generating two identical Version 4 UUIDs is astronomically low — approximately 1 in 2^122, or about 1 in 5.3 undecillion. For all practical purposes, every UUID you generate is guaranteed to be unique, even without any central coordination or registry.

UUIDs are preferred over sequential integer IDs in many scenarios because they can be generated independently on any device or system without risk of collision. This makes them ideal for distributed systems, microservices, offline-first applications, and any situation where multiple sources need to create unique identifiers without coordinating with each other.

Key Features

• Generates cryptographically random Version 4 UUIDs using the browser's Math.random() function
• Bulk generation of 1 to 100 UUIDs at once with a single click
• Four output formats: Standard (with hyphens), Compact (no hyphens), Uppercase, and With Braces
• Click any individual UUID in the list to copy it to your clipboard instantly
• Copy All button to copy the entire generated list as newline-separated text
• Running total counter showing how many UUIDs have been generated in the current session
• Scrollable output panel that accumulates UUIDs across multiple generation runs

How to Use the UUID Generator

• Step 1: Set the number of UUIDs to generate using the "Number of UUIDs" input (1 to 100)
• Step 2: Choose an output format from the dropdown — Standard, Compact, Uppercase, or With Braces
• Step 3: Click "Generate" to produce the UUIDs
• Step 4: Click any UUID in the list to copy it individually to your clipboard
• Step 5: Click "Copy All" to copy the entire list as newline-separated text
• Step 6: Click "Clear" to reset the list and start fresh

Common Use Cases

• Generating primary keys for database records in PostgreSQL, MySQL, MongoDB, or other systems that support UUID columns
• Creating unique identifiers for API resources, entities, or objects in a REST or GraphQL API
• Generating session tokens, request correlation IDs, or trace IDs for distributed system logging
• Creating unique file names for uploaded assets to prevent naming conflicts in storage systems
• Populating test data or seed scripts with realistic-looking unique identifiers
• Generating idempotency keys for payment processing or message queue systems
• Creating unique identifiers for events, transactions, or audit log entries

Tips and Best Practices

Choose your UUID format based on where you will use it. The standard hyphenated format (xxxxxxxx-xxxx-4xxx-yxxx-xxxxxxxxxxxx) is the most widely recognized and is accepted by virtually all systems that support UUIDs. The compact format (no hyphens) is useful when you need to store the UUID in a fixed-length string field or when the hyphens would cause parsing issues. The uppercase format is sometimes required by older systems or specific APIs.

When using UUIDs as database primary keys, consider the performance implications. Random UUIDs do not sort in insertion order, which can cause index fragmentation in B-tree indexes on some databases. If insert performance is critical, consider using UUID v7 (time-ordered) or a ULID instead. For most applications, however, UUID v4 performance is perfectly acceptable.

The braces format ({xxxxxxxx-xxxx-4xxx-yxxx-xxxxxxxxxxxx}) is the standard representation in Microsoft environments, including .NET, COM, and Windows Registry entries. Use this format when working with Windows APIs, COM components, or .NET applications that expect GUIDs in this notation.

Why Use UUID Generator on Webutilbox?

While most programming languages can generate UUIDs with a single function call, having a dedicated browser tool is useful for quick lookups, testing, and generating batches of UUIDs for seed data or test fixtures without writing any code. It is also accessible to non-developers who need UUIDs for configuration files, spreadsheets, or documentation.

The multiple format options and bulk generation capability make this tool more versatile than a simple one-UUID generator. Whether you need one UUID to paste into a config file or 100 UUIDs to populate a test database, this tool handles both cases with the same simple interface.

Privacy and Security

Your privacy is our priority. All processing happens entirely in your browser using JavaScript. No files, data, or inputs are ever uploaded to any server. Everything stays on your device, making this tool completely safe to use with sensitive content.