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.
