About this tool
What is the UUID Generator?
Generate UUIDs (universally-unique identifiers) for database keys, API request IDs, or any system that needs collision-free IDs. Supports UUID v4 (random — the most common), UUID v7 (timestamp-prefixed — sortable by creation order, useful for B-tree DB indices), and NanoID (shorter, URL-friendly).
Bulk generate up to 10,000 at once and export as plain text, JSON array, or CSV. Runs in browser using crypto.getRandomValues — same RNG as your password manager.
FAQ · UUID GENERATOR
Questions about the UUID Generator
What's the difference between UUID v4 and v7?
v4 is fully random — great for unguessable IDs, bad for DB indices (random insert order causes B-tree fragmentation). v7 prefixes the timestamp, so IDs sort by creation order — much better DB index performance. Modern best practice: v7 for primary keys, v4 for tokens.
Are the UUIDs guaranteed unique?
Probabilistically, yes. v4 has 122 bits of randomness — collision probability is so low you'd need to generate billions per second for thousands of years to hit one. v7 inherits v4's randomness for the trailing bits, so same guarantees.
Free?
Yes — no signup, no bulk limit (up to 10K per generation). Runs in-browser.