What's the difference between UUID v4 and v7?

v4 is fully random (128 bits of entropy). v7 includes a 48-bit timestamp prefix, making it sortable by creation time. Use v4 for maximum unlinkability (session IDs), v7 when you want database-friendly insertion order.

Are these UUIDs truly unique?

v4 UUIDs use 122 bits of randomness — the probability of a collision in a billion-entry table is below one in a quintillion. For all practical purposes they're unique, but they are not cryptographically secret — they should not be used as authentication tokens.

Can I bulk-generate thousands for test data?

Yes — the generator handles batches of 1,000+ in the browser without lag. Copy the full batch with one click and paste into a fixture file or SQL insert statement.

Developer Utilities · Free tool

UUID Generator

Generate one or many UUIDs (v4 random or v1 timestamp) instantly online. Copy single or bulk values for free, runs entirely in your browser with no sign-up.

Updated June 2026

Count

31668704-635b-43e5-8c48-394168eece67
8177a72a-f1d5-45f4-bcf0-5349bed3e04a
5e8a7a72-e18c-44a0-b18b-cad88047cce6
2eaeca0e-af5d-410a-9def-5afbfe477904
77b052a8-5c70-4fdb-a6ef-048ee219c5ca

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What it does

A free UUID (v4) generator. Generates cryptographically random UUIDs in your browser. Batch generation up to 50 at a time.

UUIDs are essential for database primary keys, session IDs, and anywhere you need a globally unique identifier that can’t be guessed. Uses crypto.randomUUID() when available, cryptographic fallback otherwise.

Embed this tool on your siteShow snippet

Paste this snippet into any page. Loads on-demand (lazy), no tracking scripts, and sized to most dashboards. Replace the height to fit your layout.

<iframe src="https://freetoolarena.com/embed/uuid-generator" width="100%" height="720" frameborder="0" loading="lazy" title="UUID Generator" style="border:1px solid #e2e8f0;border-radius:12px;max-width:720px;"></iframe>

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How to use it

Set how many UUIDs to generate.
Click Generate.
Copy individual UUIDs or the whole batch.
Regenerate any time for a fresh batch.

Frequently asked questions

What's the difference between UUID v4 and v7?: v4 is fully random (128 bits of entropy). v7 includes a 48-bit timestamp prefix, making it sortable by creation time. Use v4 for maximum unlinkability (session IDs), v7 when you want database-friendly insertion order.
Are these UUIDs truly unique?: v4 UUIDs use 122 bits of randomness — the probability of a collision in a billion-entry table is below one in a quintillion. For all practical purposes they're unique, but they are not cryptographically secret — they should not be used as authentication tokens.
Can I bulk-generate thousands for test data?: Yes — the generator handles batches of 1,000+ in the browser without lag. Copy the full batch with one click and paste into a fixture file or SQL insert statement.

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