UUID Generator - Free Online GUID Maker

A UUID generator creates universally unique identifiers, 128-bit values formatted as 32 hexadecimal digits in five groups. Use them as database keys, session tokens, or file names when you need IDs that won't collide across systems. This tool generates version 4 (random) UUIDs locally in your browser.

1. Choose quantity: Pick how many UUIDs you need.
2. Select format: Choose standard (lowercase with dashes), uppercase, or no dashes.
3. Generate: Click Generate and copy or download the list.

• Collision-proof: Version 4 UUIDs have a near-zero chance of duplicates.
• No coordination: Generate IDs without checking a central database.
• Format options: Match the style your system expects.

Use case 1: Database primary keys

Create unique row IDs before inserting records, avoiding auto-increment conflicts in distributed systems.

Use case 2: API request tracing

Tag each request with a UUID to track it through logs and microservices.

Use case 3: File naming

Name uploads or exports with UUIDs to avoid overwrites and ensure uniqueness.

Basic example

Quantity: 1
Output: f47ac10b-58cc-4372-a567-0e02b2c3d479

Advanced example

Quantity: 5, uppercase, no dashes
Output:

A1B2C3D4E5F6789012345678901234AB
B2C3D4E5F6789012345678901234ABCD
C3D4E5F6789012345678901234ABCDEF
D4E5F6789012345678901234ABCDEF01
E5F6789012345678901234ABCDEF0123

UUIDs as security tokens

UUIDs are unique but not secret. Don't use them alone for authentication; combine with proper auth tokens.

Version confusion

This tool generates v4 (random) UUIDs. If you need v1 (timestamp-based) or v5 (namespace), use a library.

• Store UUIDs as 16-byte binary in databases for space efficiency; display as hex for readability.
• Use lowercase with dashes for standard formatting; uppercase without dashes for compact storage.
• Pair with the Base64 encoder if you need shorter URL-safe IDs.

• Create secure passwords with the password generator.
• Generate random numbers using the random number generator.
• Hash values with the MD5 generator or SHA generator.

UUID generation happens locally in your browser using the Web Crypto API. No IDs are uploaded or logged.