To generate a UUID online, click the Generate button. The tool creates cryptographically random UUID v4 identifiers using your browser's built-in crypto API. Generate one or many at once.
Create RFC-style random UUIDs on demand—copy one or many without signing up.
Last updated: 2026-05-07
✓ All processing happens in your browser✓ No sign-up required✓ 78 developer tools available✓ Built by developers, for developers
What is UUID Generator?
UUID Generator creates cryptographically random UUID v4 identifiers for databases, APIs, and testing. Generate one or hundreds at once.
Benefits of UUID Generator
No collision risk across distributed systems
Works without database auto-increment
Suitable for client-generated IDs
Fast generation with no server dependency
Features
UUID v4 generation with crypto-grade randomness
Batch generation of multiple UUIDs
One-click copy to clipboard
Lowercase and uppercase format options
Common use cases
Generating primary keys for database records
Creating unique request IDs for API tracing
Populating test fixtures with realistic IDs
Assigning session identifiers
Quick steps to use UUID Generator
Scroll to the workspace below—this same page loads the interactive tool.
Paste or type your input, then run the primary action.
Copy the output or switch tabs to another Developer Friend utility.
For long documents, combine with our JSON formatter, diff, or API tester as needed.
Detailed guide and reference: UUID Generator
How to Use UUID Generator
Click Generate — Press the Generate button to create a new random UUID v4.
Generate multiples — Adjust the count to generate multiple UUIDs at once for batch operations.
Copy UUIDs — Click copy to grab one or all generated UUIDs for your database seeds or API requests.
When UUIDs beat incremental IDs
UUIDs avoid collisions across services and databases without a central allocator. They are common in public APIs, event sourcing, and client-generated IDs before a server round-trip.
Version 4 (random) at a glance
UUID v4 is random (with a few fixed version bits). It is not guaranteed sortable or human-meaningful—use ULID or time-ordered IDs if you need chronological clustering.
Testing and fixtures
Generate batches for seed data, mock APIs, and integration tests. Pair with JSON formatter when embedding UUIDs into larger JSON payloads.
Privacy
IDs are generated with crypto-grade randomness in the browser. They are not logged by Developer Friend unless you use a separate sharing feature intentionally.
Example Usage
Generate a UUID v4
Input:
(click Generate)
Output:
f47ac10b-58cc-4372-a567-0e02b2c3d479
Each generated UUID is a cryptographically random 128-bit identifier.
Key Features and Benefits
Key Features
UUID v4 generation with crypto-grade randomness
Batch generation of multiple UUIDs
One-click copy to clipboard
Lowercase and uppercase format options
Benefits
No collision risk across distributed systems
Works without database auto-increment
Suitable for client-generated IDs
Fast generation with no server dependency
Common Use Cases
Generating primary keys for database records
Creating unique request IDs for API tracing
Populating test fixtures with realistic IDs
Assigning session identifiers
Best Practices
Use UUID v4 for general-purpose unique identifiers in APIs and databases.
Consider ULID or UUID v7 when you need time-sorted identifiers.
Store UUIDs as 16-byte binary in databases for better storage and index performance.
Always generate UUIDs using cryptographically secure random sources.
Common Mistakes to Avoid
Using Math.random() instead of crypto.getRandomValues() for UUID generation.
Storing UUIDs as VARCHAR(36) instead of a native UUID or BINARY(16) column type.
Relying on UUID v4 for time-ordering — use UUID v7 or ULID for chronological sorting.
How this compares to alternatives
UUID Generator on Developer Friend is aimed at fast paste-and-run workflows in a browser tab: no install, no sign-up, and copy-friendly output. Full desktop suites (IDEs, Postman) are stronger for saved projects and team collaboration; CLI and language libraries are better for automation and CI. Choose this tool when you want immediate feedback and, for most utilities, processing that stays on your device.
Frequently Asked Questions about UUID Generator
What is a UUID?
A UUID (Universally Unique Identifier) is a 128-bit identifier used to uniquely identify resources without a central authority. Version 4 UUIDs are randomly generated.
Are UUIDs truly unique?
UUID v4 uses 122 random bits, making collision probability astronomically low — safe for virtually all practical applications.
What is the difference between UUID and GUID?
They are the same thing. GUID (Globally Unique Identifier) is Microsoft's term for UUID.
Is the UUID Generator on Developer Friend free?
Yes. UUID Generator and every other utility on Developer Friend are free to use in your browser. There is no sign-up wall and no paywall for core features.
Does my data leave my device when I use UUID Generator?
By default, UUID Generator runs entirely in your browser. Your input is not uploaded to Developer Friend servers unless the tool explicitly performs a network request you start (for example, an API test or DNS lookup).
Can I use UUID Generator offline?
After the first load, Developer Friend is cached by your browser and most tools work offline. Tools that need live network access still require a connection.
Who is Developer Friend for?
Developer Friend is built for software engineers, QA, DevOps, and technical writers who need fast formatters, encoders, and API helpers without installing desktop software.
How many tools are on Developer Friend?
Developer Friend offers 78+ free developer tools across JSON, API, encoding, time, Dev, and AI-assisted workflows.
Developer Friend is a free workspace with 78+ developer tools for JSON, APIs, encoding, time math, Dev utilities, and optional AI-assisted explainers. It is built for engineers who want fast answers in a browser tab without installing desktop software.
Privacy assurance
All processing happens in your browser for tools that do not initiate a network call. Sensitive payloads like JWTs, .env excerpts, and SQL drafts stay on your device unless you deliberately use a networked feature.
Why teams trust the platform
The interface is keyboard-friendly, theme-aware, and consistent across tools so you can move from formatting JSON to testing an API without relearning controls. There are no paywalls on core utilities and no sign-up requirement for day-to-day use.