UUID Generator (v4 and v7)
Create as many UUIDs as you need for database keys, test fixtures or file names. Choose classic random v4, or v7, which embeds a timestamp so IDs sort in creation order.
IDs are generated locally with crypto.getRandomValues; no server is involved.
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How to use
- Choose UUID v4 or v7.
- Enter how many to generate (1–1000).
- Optionally switch to uppercase, remove hyphens or wrap in braces.
- Copy all of them or download a .txt file.
Features and limits
- v4 fills 122 bits with random data and carries no information about when it was created.
- v7 (RFC 9562) starts with a millisecond Unix timestamp, so values sort by creation time even as plain strings.
- Randomness comes from the browser's cryptographically secure generator, crypto.getRandomValues.
- Formatting options: uppercase, without hyphens, and {braces} as used by some Microsoft tools.
FAQ
Should I use UUID v4 or v7 for database primary keys?
v7 is usually the better fit because new IDs are roughly sequential, which keeps B-tree indexes compact. Use v4 if you don't want the creation time to be visible in the ID.
Can two UUIDs ever be the same?
In theory yes, but with 122 random bits in v4 the chance of a collision is negligible in practice.
Is a GUID the same as a UUID?
Yes. GUID is Microsoft's name for the same 128-bit format; enable the braces option if you need the {…} style.
Can I read the timestamp from a UUID v7?
Yes. The first 48 bits are the Unix time in milliseconds when the UUID was generated.