About UUID Generator

Generate v4 UUIDs — single or bulk. Part of the DevTools Surf developer suite. Browse more tools in the Generators collection.

Use Cases

• Seed test databases with unique IDs
• Generate API keys, session tokens, or correlation IDs
• Create placeholder foreign keys when sketching a schema
• Assign unique IDs to client-side drafts before they sync

Tips

• Generate up to 100 UUIDs at once
• Toggle uppercase or remove dashes for different formats
• Each UUID has a copy button on hover

Fun Facts

• UUID v4 uses 122 random bits, giving 5.3 x 10^36 possible values. You'd need to generate 1 billion UUIDs per second for 85 years to have a 50% chance of collision.
• UUID v7 (RFC 9562, 2024) embeds a Unix timestamp in the first 48 bits, making UUIDs sortable by creation time while staying globally unique.
• Microsoft calls UUIDs 'GUIDs' (Globally Unique Identifiers) — they are identical in format but the name stuck in the Windows ecosystem.

FAQ

UUID v4 or v7?

Both supported. v4 is purely random; v7 embeds a millisecond timestamp prefix for sortability. v7 is the 2024 addition to RFC 9562; modern systems should prefer it.

Is it crypto-safe?

Yes — v4 uses crypto.getRandomValues for the random bits. v7's timestamp is deterministic (that's the point) but the random tail is crypto-secure.

Can I generate in bulk?

Up to 100 at once. For larger batches, use a command-line UUID tool or a database function (gen_random_uuid() in Postgres).

Is this the same as GUID?

Yes — Microsoft's 'GUID' is Windows terminology for UUID. Same format, same semantics. Use UUID on cross-platform projects to avoid confusion.