Free UUID Generator
Generate UUIDs in bulk. Choose v4 (cryptographically random, the most common) or v7 (timestamp-sortable, ideal for database keys). Copy all or one at a time.
- 1.
074ffb35-37b0-4d01-b48b-286952925657 - 2.
22e5a794-2dc5-477e-8470-73918b590ec2 - 3.
22cac4a4-19c3-4163-97fa-4ef8d2b9c8a2 - 4.
2d069e85-9031-4f23-90de-19929a965084 - 5.
d6c0ad79-d504-4e15-b65c-a65079b0ad81
Inspect a UUID
v4 vs v7 — which to use?
- v4: 122 bits of randomness, no timestamp. Universal default.
- v7: prefixes a millisecond timestamp, then random bits. Sortable in databases — better for primary keys because new rows insert near the end of the index.
- For most APIs and tokens, v4 is fine. If you're choosing a database PK that you also insert as the cluster key, v7 reduces index fragmentation dramatically.
Frequently asked questions
What's the difference between UUID v1, v4, ULID, and NanoID?
UUID v1 is timestamp-based (sortable but leaks time/MAC). UUID v4 is fully random (128 bits, the default for most use cases). ULID is timestamp-prefixed and lexicographically sortable (good for databases). NanoID is shorter (21 chars vs 36) but equally collision-resistant — good for URLs.
Can I generate UUIDs in bulk?
Yes. Pick a count up to 10,000 — the tool generates them instantly client-side using crypto.getRandomValues for cryptographic-grade randomness.
Are these UUIDs cryptographically secure?
v4 and NanoID use the Web Crypto API (crypto.getRandomValues), which is cryptographically secure. v1 is NOT secure for unguessable IDs (timestamp leak).
Can I use these as database primary keys?
Yes — UUID v4 and ULID are both designed for that. ULID is preferable in Postgres / MySQL because its lexicographic order plays nicely with B-tree indexes; UUID v4's randomness can cause index fragmentation.
Generate UUID v1, v4, ULID, and NanoID — bulk mode supported, all cryptographically secure where applicable.
How to use
- 1Pick the ID type (v4 most common, ULID for sortable DB keys, NanoID for short URLs).
- 2Set the count (1 to 10,000).
- 3Click generate — IDs appear instantly.
- 4Copy individually or all at once, or download as a list.
Why use this tool
- Four ID types — covers every modern use case.
- Crypto.getRandomValues — true randomness, not Math.random.
- Bulk export — 10K IDs in under a second.
Real-world examples
Database primary keys
ULID type → 10,000 IDs → all timestamp-ordered for B-tree friendly Postgres / MySQL inserts.
Short URL slugs
NanoID type → 21-char unguessable IDs → perfect for /share/<id> URLs.
Test data
v4 bulk → 1000 IDs for seeding a test database with unique users.