UUID Generator
Generate a random UUID instantly. This free online UUID generator creates RFC 9562 compliant identifiers (v4, v7, v1, and Nil) locally in your browser — your data never leaves your device.
What is a UUID?
A UUID (Universally Unique Identifier) is a 128-bit value used to uniquely identify information in computer systems without a central coordinating authority. Written as 32 hexadecimal digits in the 8-4-4-4-12 pattern, a UUID looks like 550e8400-e29b-41d4-a716-446655440000.
Because they can be generated independently on any machine with a negligible chance of collision, UUIDs are ideal for database primary keys, distributed systems, message identifiers, and API resource IDs. UUID and GUID refer to the same 128-bit standard — GUID is simply the name Microsoft uses.
Why use localguid?
Generated locally in your browser
Values are created on your device using the Web Crypto API. Nothing is transmitted, logged, or stored on a server — the page even works offline once loaded.
Cryptographically secure randomness
Version 4 identifiers use crypto.getRandomValues() for high-entropy randomness, so collisions are astronomically unlikely.
Multiple versions & formats
Switch between v4 (random), v7 (time-ordered), v1 (timestamp), and Nil. Toggle uppercase, hyphens, and braces to match your platform.
Single or bulk output
Copy one value with a click, or generate thousands at once and download them as a plain-text file for seeding databases and tests.
Common use cases
Database primary keys
Assign unique IDs to rows without a central sequence. UUID v7 is especially good here because it is time-ordered and keeps inserts index-friendly.
Distributed systems
Generate identifiers on many nodes at once — no coordination required — for events, jobs, and messages across queues like Kafka or SQS.
API & resource identifiers
Expose opaque, non-sequential IDs in URLs and payloads so internal counts and record volumes stay private.
Idempotency & correlation keys
Tag requests and traces with a unique key to safely retry operations and correlate logs across services.
Frequently asked questions
What is the difference between a UUID and a GUID?
None technically — both are 128-bit identifiers defined by the same standard (RFC 9562, previously RFC 4122). 'UUID' is the term used across most languages and open-source software, while 'GUID' is the term Microsoft uses in Windows, .NET, and SQL Server. You can use them interchangeably.
Is this UUID generator cryptographically secure?
Yes. Version 4 UUIDs are produced with the browser's built-in Web Crypto API (crypto.getRandomValues), which is a cryptographically secure source of randomness. The uniqueness of v4 comes from 122 bits of randomness.
Are my generated UUIDs private?
Completely. Every UUID is generated on your own device in JavaScript. Nothing is sent to a server, nothing is stored, and there are no ads or trackers reading your values. The tool keeps working even if you go offline after loading it.
Which UUID version should I use?
Use v4 for general-purpose random IDs — it is the most common choice. Use v7 when you want time-ordered keys that sort naturally and keep database indexes efficient. v1 encodes a timestamp and node, and Nil is the all-zero placeholder value.
How many UUIDs can I generate at once?
Up to 10,000 at a time using bulk generation. You can copy the entire list to your clipboard or download it as a .txt file for seeding databases and test fixtures.