UUID Generator — Generate UUIDs Online Free
Generate cryptographically random UUID v4 values with options for bulk generation, case, and formatting. Instantly. No sign-up required.
How to uuid generator
- 1Click 'Generate UUID' to create a new UUID v4
- 2Set the quantity (1-100) to generate multiple UUIDs at once
- 3Toggle uppercase/lowercase and include/exclude hyphens to match your format
- 4Click 'Copy' to copy the generated UUIDs to your clipboard
About This Tool
A UUID generator creates universally unique identifiers — 128-bit values that are virtually guaranteed to be unique across all systems without a central registry. UUID v4 values are generated using cryptographically secure random numbers, making them ideal for database primary keys, session tokens, API request IDs, and distributed system identifiers.
This free UUID generator uses the browser's crypto.randomUUID() API when available, with a fallback to crypto.getRandomValues() for older browsers. Both methods produce cryptographically secure random values. You can generate up to 100 UUIDs at once, toggle between uppercase and lowercase, and choose whether to include or exclude hyphens depending on your project's requirements.
All generation happens locally in your browser. No UUIDs are sent to a server or stored anywhere, ensuring that your identifiers remain private. There are no usage limits and no account required.
Frequently Asked Questions
UUID v4 is a version of the Universally Unique Identifier standard that uses random or pseudo-random numbers. The standard format is 8-4-4-4-12 hexadecimal characters with hyphens, like 550e8400-e29b-41d4-a716-446655440000. The '4' in the third group indicates the version.
UUID v4 uses 122 bits of randomness, giving over 5.3 x 10^36 possible values. The probability of generating two identical UUIDs is astronomically small — you would need to generate about a billion UUIDs per second for 85 years to have a 50% chance of a single collision.
Yes. The tool uses crypto.randomUUID() or crypto.getRandomValues(), both of which use the browser's cryptographically secure random number generator. These are suitable for security-sensitive applications.
Some systems and databases store UUIDs without hyphens to save space (32 hex characters instead of 36). The hyphenless format is common in URLs, file names, and compact storage formats. Both formats represent the same 128-bit value.
No. All generation happens locally in your browser. No UUIDs are sent to any server and none are stored or logged.