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Generate v4 (purely random) or v7 (time-ordered, monotonic) UUIDs. Bulk generation up to 1000 at once.

last reviewed 2026-04-27·client-side · 0 bytes sent
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Hash
SHA-256.
Timestamp
Unix & ISO.
JSON
Format.
Base64
Encode/decode.

v4 vs v7 - when to use which

v4: 122 bits of randomness. Standard for "I just need a unique ID." 5.3×10³⁶ unique values - collision practically impossible.

v7 (RFC 9562, 2024): first 48 bits are a Unix millisecond timestamp, then 74 bits of randomness. Sortable by creation time, which matters for database B-tree indexes (random UUIDs cause page splits; v7s don't). Use v7 for primary keys in new systems.

Common questions

Is UUID Generator free to use?

Yes. The tool runs in your browser at no cost, with no signup required.

Where is the math performed?

Calculations run locally in your browser. Your inputs do not leave your device.

Are the rates and rules current?

We update sources when published rates change. For high-stakes decisions, verify against the official source linked on this page.