UUID Generator

A UUID (Universally Unique Identifier) Generator creates RFC 4122-compliant version 4 UUIDs — 128-bit random identifiers formatted as a 32-character hexadecimal string split into five groups, like 550e8400-e29b-41d4-a716-446655440000. UUID v4 relies on cryptographically strong random number generation, making the probability of collision astronomically low — suitable for virtually any use case that requires globally unique identifiers without a central authority.

For developers, UUIDs are a foundational primitive. Rather than relying on sequential auto-increment IDs from a database, UUIDs can be generated client-side, distributed across services, or embedded in URLs without exposing record counts or creating enumeration vulnerabilities. They're the standard choice for primary keys in relational databases, document IDs in NoSQL stores, correlation IDs in distributed tracing, and entity references in REST and GraphQL APIs.

Using the tool is straightforward: click the Generate button and a fresh UUID v4 is instantly produced in the standard xxxxxxxx-xxxx-4xxx-yxxx-xxxxxxxxxxxx format. You can generate a single UUID or — if batch generation is supported — specify a count to receive multiple unique identifiers at once, one per line. Each result can be copied to your clipboard with a single click, ready to paste directly into your code, database seed file, or API request.

The output is always lowercase and hyphen-delimited by default, matching the most widely accepted convention across languages and frameworks. If your target system requires an uppercase or stripped (no-hyphen) format, you can copy the result and apply a quick transform — or check whether your framework provides a built-in normalizer. Most databases and ORMs accept both cased variants and will store them identically.

One important edge case: UUID v4 is random, not sequential. This means inserting UUIDs as primary keys in a B-tree index (like PostgreSQL or MySQL) can cause index fragmentation over time at high insert volumes. In those scenarios, consider UUID v7 or ULID formats, which embed a timestamp prefix for monotonic ordering. For the vast majority of applications, however, UUID v4 is the safest and simplest choice.