UUID Generator — Generate UUID v4 Online

What is a UUID?

A UUID (Universally Unique Identifier) is a 128-bit number represented as a 32-character hexadecimal string in the format `xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx`. UUID v4 is generated using random or pseudo-random numbers. There are 5.3 × 10³⁶ possible UUIDs — making collisions astronomically unlikely.

Why Use UUIDs?

Sequential integer IDs expose information (how many records exist, the order they were created). They also create challenges in distributed systems where multiple nodes insert records simultaneously. UUIDs solve both: they're opaque and can be generated independently on any client without coordination.

Key Benefits

• Generate single or bulk UUIDs (up to 100 at once)
• RFC 4122 compliant UUID v4
• Uses browser's native crypto.randomUUID()
• Copy individually or all at once
• Free with no account

How to Use UUID Generator

1. Click Generate for one UUID
2. Set count for bulk generation
3. Copy individual UUIDs or click Copy All
4. Paste into your code, database, or config

Example Use Case

Seeding a database with test records. Each record needs a unique ID before insert (so foreign keys can be set up ahead of time). Generate 50 UUIDs at once, copy all, paste into the seed script.

Tips

• UUID v4 is the most common — use it unless you have a specific reason for v1 or v5
• UUIDs are case-insensitive — both uppercase and lowercase are valid
• Storing UUIDs in databases: use a UUID type column or CHAR(36)
• UUID v1 includes timestamp and MAC address — UUID v4 is preferable for privacy