UUID Generator

Generate UUID v4 locally. No uploads.

Settings
Lines: 0 • Chars: 0
Result

What is a UUID?

A UUID (Universally Unique Identifier) is a 128-bit value represented as a string of hexadecimal digits. It is designed to be unique across time and space without the need for a central authority or database sequence. UUIDs are widely used as identifiers for database rows, API resources, events, sessions and correlation IDs in distributed systems.

UUID v4 format

This tool generates random UUID version 4 values in the standard 36-character format:

xxxxxxxx-xxxx-4xxx-yxxx-xxxxxxxxxxxx

The 4 indicates version 4 (random), and the y nibble encodes the variant. The remaining digits are generated from cryptographically strong random bytes provided by the browser'scrypto.getRandomValues() API when available.

Typical use cases for UUIDs

  • Primary keys for rows in relational or NoSQL databases
  • Public identifiers for REST API resources instead of incremental IDs
  • Correlation IDs for tracing requests across microservices
  • Identifiers for background jobs, messages and events
  • Temporary tokens for file uploads, invites or one-time links

Advantages of UUID v4

  • No need for a central sequence generator or auto-increment column
  • Identifiers can be generated on the client or in multiple services independently
  • Harder to guess internal counts (compared to sequential numeric IDs)
  • Good fit for sharded or multi-region databases

Example UUIDs

f8b8aa19-7f7a-4f26-9baf-9f2a67e9585c
1c4c3e19-3e6d-4c2d-9a40-2f0b6a3b3b5e
8e3f7b2a-2bc1-4f9e-a16e-656c3fda8079

Things to keep in mind

  • Although collisions are extremely unlikely, UUIDs are not a replacement for proper uniqueness constraints in your database.
  • UUID v4 is random; if you need time-ordered identifiers, consider ULID or UUID v7 style IDs in combination with this tool for experimentation.
  • UUIDs are not secrets. Do not treat them as secure tokens or passwords.

Is this UUID generator secure?

This generator runs entirely in your browser. When supported, it uses the Web Crypto API (crypto.getRandomValues) to produce high-quality random bytes. No identifiers are sent to any server or logged remotely, making the tool safe for use in development and test environments.

Related tools

  • JSON Formatter – inspect JSON documents that contain UUID keys
  • Base64 – encode or embed UUIDs in tokens and URLs
  • Regex Tester – validate UUID formats with regular expressions
  • Cron Builder – schedule jobs that operate on UUID-tagged entities

UUIDs are a practical choice for identifiers in modern distributed systems. A reliable client-side generator helps you quickly produce test values and prototype new APIs without depending on any external service.