Create UUID v4 identifiers
Generate one or many UUIDs in your browser. No upload. No account. Copy ready for APIs, databases, and tests.
- UUID v4
- Runs in your browser
- Nothing uploaded
- No account
Ready. Click Generate UUID for a UUID v4.
What this tool does
This UUID generator creates random UUID version 4 values for primary keys, request IDs, and test fixtures. Generation runs locally with the Web Crypto API. Prefer this over sequential IDs when you need opaque, collision-resistant identifiers without a central counter.
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FAQ
What is a UUID generator?
A UUID generator creates Universally Unique Identifiers (also called GUIDs). This page generates UUID version 4 values using the browser's crypto.randomUUID API when available, or a secure random fallback that sets the RFC 4122 version and variant bits.
Does this UUID generator send anything to a server?
No. UUIDs are created entirely in your browser. Nothing is uploaded, logged, or stored on a server.
Is UUID v4 the same as a GUID?
GUID usually means the same 128-bit identifier family as UUID. UUID v4 is a random UUID (version 4). This tool outputs the common 8-4-4-4-12 lowercase hex form with hyphens.
Are generated UUIDs guaranteed unique?
UUID v4 collision risk is astronomically low for normal app use when the random source is cryptographically strong. This page uses crypto.getRandomValues / crypto.randomUUID when the browser provides them. It does not contact a central registry.
Can I generate multiple UUIDs at once?
Yes. Choose a count from 1 to 100, then Generate. Each line is one UUID. Use Copy all to put the list on the clipboard.