Generate universally unique identifiers (UUIDs) with a single click.
A UUID generator for the moments you need a unique ID right now: a primary key for a test row, a request ID for a log line, a fixture value for a unit test. Choose version 4 (random) or version 1 (time-based), click Generate, and copy. Generation happens in your browser, so the IDs are not requested from or logged by a server.
v4 (random) is the standard choice for almost everything — database primary keys, API tokens, request IDs. v1 (timestamp-based) is useful when you specifically want IDs that sort roughly by creation time.
Not mathematically guaranteed, but the collision probability for v4 UUIDs is astronomically small — you'd need to generate billions of them per second for centuries before a collision became likely.
v4 UUIDs use a cryptographically random source in modern browsers (crypto.randomUUID), so they're reasonable as unguessable identifiers, though a purpose-built token generator is still preferable for authentication secrets.
Yes. GUID is the name Microsoft tools and .NET use for the same 128-bit identifier, written as 32 hexadecimal digits in groups of 8-4-4-4-12. A value generated here can be used anywhere either name is expected.
This tool adds one UUID to the list per click, newest at the top. If you need a whole table of rows with UUIDs in a column, the Mock Data Generator has a UUID field type and can output many rows as JSON or CSV in one go.
Version 4 UUIDs come from the browser crypto.randomUUID function, which browsers only expose on HTTPS pages and on localhost. If you opened the site over plain HTTP, switch to the HTTPS address.
A version 1 UUID encodes the time it was created, which is why these IDs sort roughly by creation time. The node part of the ID is generated randomly in the tool, not read from your network card, so it does not contain your MAC address.
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