How many UUIDs can I generate at once?
Up to 100 per batch — pick 1, 10, 50, or 100.
UUID Bulk Generator
Configuration
Generated UUIDs
Generated UUIDs will appear here.
Version reference
| Version | Basis | Sortable by creation time | Collision probability | Typical use |
|---|---|---|---|---|
| v1 | Timestamp (100ns ticks since 1582) + clock sequence + node ID | Roughly, within the same generator — timestamp bits aren't contiguous in the byte layout, so naive byte-sortability is worse than v7 | Extremely low in practice; theoretically guessable if timestamp and node ID are both known/narrow | Legacy systems that already standardized on v1; distributed IDs where rough recency matters more than a real random ID |
| v3 | MD5(namespace UUID + name) | No — deterministic, not time-based | Tied to MD5's collision resistance (weak in general, but a practical concern only if an attacker can choose the name input) | Deterministic IDs: same namespace+name must always produce the same UUID (e.g. mapping a URL or filename to a stable ID) |
| v4 | 122 bits of randomness | No — fully random | ~50% chance of any collision only after generating ~2.71 × 10¹⁸ UUIDs (billions of IDs/second for centuries) | The default general-purpose choice: session IDs, request IDs, anything that doesn't need to be sortable or deterministic |
| v5 | SHA-1(namespace UUID + name) | No — deterministic, not time-based | Same idea as v3 but with SHA-1 — the RFC-recommended choice over v3 when a name-based UUID is needed | Same use case as v3; prefer v5 over v3 for new systems since SHA-1 is a stronger hash than MD5 |
| v7 | Unix timestamp (ms, 48 bits) + 74 bits of randomness | Yes — the timestamp occupies the leading bytes, so lexicographic/byte sort order matches creation order | Still very low: 74 random bits per millisecond, effectively no realistic collision risk at normal generation rates | Database primary keys and anything indexed — sorts naturally, giving better index locality than v4 while staying essentially as collision-resistant |
Privacy note (v1): Classic RFC 4122 v1 embeds the generating machine's real MAC address in the node-ID field — a known privacy/fingerprinting concern. This tool does not do that: browsers have no access to hardware MAC addresses, so v1 here uses a random node ID with the multicast bit set, per RFC 4122 §4.5's explicit allowance for exactly this case.
About this UUID Bulk Generator
Generate large batches of UUID v1, v4, and v7 values, or name-based v3/v5 UUIDs, securely in your browser.
UUIDs are generated locally using the Web Crypto API. Nothing is uploaded or stored.
FAQ
Will any generated UUIDs collide with each other?
Effectively no — even at the maximum batch size, the odds of a duplicate v4 UUID are astronomically small given 122 bits of randomness per value.
What formats can I export the list in?
CSV or JSON, via the download buttons — or copy the whole batch to the clipboard at once.
Why use bulk generation instead of one at a time?
Seeding a database, mocking API responses, or building test fixtures usually needs many unique IDs at once — one-by-one doesn't scale for that.
Which UUID version does bulk generation use?
Whichever you pick — v1, v3, v4, v5, or v7, same as the single UUID Generator. v3/v5 need a namespace and name since they're deterministic rather than random.
Is the generated list uploaded anywhere?
No — generated and formatted entirely in your browser.
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