Free Online UUID Generator
Generate cryptographically random UUIDs (GUIDs) — one, or up to 1,000 at a time.
Tip: Ctrl + Enter generates a fresh batch
Check a UUID
Paste any UUID to validate it and see its version.
How it works
- Choose v4 (random) or v7 (time-ordered).
- Enter how many UUIDs you need — up to 1,000 at once.
- Pick a format: uppercase, without hyphens, with braces or quotes.
- Copy all or download them as uuids.txt.
Frequently asked questions
What is a UUID?
A UUID (universally unique identifier), also called a GUID, is a 128-bit value written as 32 hexadecimal digits like 123e4567-e89b-42d3-a456-426614174000. It lets systems create IDs independently without coordinating to avoid duplicates.
Should I use UUID v4 or v7?
v4 is fully random and the most widely supported. v7 starts with a timestamp, so new IDs sort in creation order — this makes database indexes faster and is a great default for new primary keys.
Can two generated UUIDs ever collide?
In practice, no. A v4 UUID has 122 random bits; you would need to generate billions per second for many years before a duplicate becomes likely. We use your browser's cryptographically secure random generator.
Are the UUIDs stored or logged?
No. UUIDs are generated in your browser and never sent to our servers, so you can safely use them as real identifiers.
Generate UUIDs for databases, APIs and testing
UUIDs give every record, file or message an identifier that is unique without asking a central server. They are used as database primary keys, request IDs in logs, file names and test fixtures.
UUID versions at a glance
- Version 4 — 122 random bits. The most common choice and supported everywhere.
- Version 7 — starts with a millisecond timestamp followed by random bits, defined in RFC 9562 (2024). IDs sort by creation time, which keeps database indexes compact and fast.
Formatting options
The standard format is lowercase with hyphens (8-4-4-4-12). Some Microsoft tools expect uppercase GUIDs in braces, and some systems store UUIDs as 32 hex characters without hyphens. Choose the format your system needs, then copy all or download them as a text file.
Validate an existing UUID
Paste any UUID into the checker to confirm it is well-formed and see its version and variant. For version 7 UUIDs, the creation time is decoded too.