UUID Generator
Generate unique UUIDs (v4) for your applications instantly.
What is this tool? UUID Generator?
How do you use this tool? UUID Generator
- A single UUID v4 is generated automatically when the page loads.
- Click Generate to create a new random UUID, or use the bulk generator to produce up to 100 at once.
- Toggle uppercase/lowercase and with/without hyphens to match your requirements.
- Click any UUID to copy it to your clipboard instantly.
Common Use Cases
Database primary keys
Use UUIDs instead of auto-increment integers to avoid exposing row counts and to make IDs safe to generate offline or client-side.
API resource identifiers
Give every resource in a REST or GraphQL API a globally unique, non-guessable identifier.
Session & auth tokens
Generate unique tokens for sessions, password-reset links, or one-time invite codes.
Distributed systems
Create unique IDs on multiple servers or devices at once without a central counter or coordination service.
File & object naming
Avoid filename collisions when users upload files, by appending or replacing the name with a UUID.
Why is this tool useful?
Runs entirely in your browser
UUIDs are generated locally using your browser's random number generator. Nothing is sent to a server or logged.
Practically collision-free
A UUID v4 has 122 random bits, about 5.3 × 10^36 possible values, so accidental duplicates are not a practical concern.
Bulk generation
Need more than one? Generate up to 100 UUIDs at once and copy them all in a single click.
Flexible formatting
Toggle uppercase/lowercase and with/without hyphens to match the convention your database, language, or API expects.
Best Practices
- ✓ Don't rely on a UUID alone as an access-control mechanism, an unguessable ID is not the same as an authorization check.
- ✓ Store UUIDs using your database's native UUID/binary(16) column type rather than a 36-character string, to keep indexes smaller and lookups faster.
- ✓ Use UUID v4 for general-purpose unique IDs; reach for UUID v7 instead if you need IDs that sort roughly by creation time.
- ✓ Keep formatting consistent across your system, lowercase with hyphens (the canonical RFC 4122 form) is the most widely compatible choice.
- ✓ Avoid UUID v1 for anything public-facing: it embeds a timestamp and, on some systems, the generating machine's MAC address.
Practical examples
Version: UUID v4, quantity: 3.
550e8400-e29b-41d4-a716-446655440000 6f1b7f86-5f28-4aac-8e93-bf3e6e44d7c1 8c6ab2c8-4d2f-45df-b3de-53a34fb57578 These are illustrative valid-format values. A new generation produces different UUIDs.
Frequently Asked Questions
UUID v4 is a randomly generated universally unique identifier. It contains 122 random bits, giving a total of 2^122 possible values, making accidental collisions practically impossible.
Use UUIDs as primary keys in databases, unique identifiers for API resources, session tokens, file names, and anywhere you need a globally unique string that doesn't expose sequential information.
While not mathematically guaranteed, the probability of two randomly generated UUIDs colliding is astronomically low, about 1 in 5.3 × 10^36. In practice, they are treated as unique.
v1 is time-based (may expose the machine's MAC address), v4 is fully random, and v7 (newer) combines a timestamp with randomness for sortability. v4 is the most widely used for general purposes.
Yes. Enter a count between 1 and 100 in the bulk generator and click Bulk Generate. All UUIDs are displayed in a scrollable list and can be copied to your clipboard with a single click.
No. The tool creates a new result in the browser. Your original remains unchanged unless you overwrite it after downloading.
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