UUID Generator - Free Online UUID v4 & GUID Generator

How to Use This Free Online UUID Generator

Click Generate to produce a new UUID v4.
Use the Bulk mode to generate 10, 50, or 100 UUIDs at once.
Click any UUID to copy it to the clipboard.
Toggle uppercase/lowercase and hyphen format options.

UUID Generator: generate unique UUID v4 and GUID strings instantly for your development projects. A Universally Unique Identifier is a 128-bit number used to identify information in computer systems without significant central coordination. This random uuid creator ensures that every generated string follows the RFC 4122 specification, making it a reliable unique identifier generator for databases and session management.

Applications for a Bulk UUID Generator

Developers often require an online guid maker when setting up new database schemas or testing distributed systems. This tool functions as a high-performance bulk uuid generator, allowing you to create hundreds of random unique ids in a single click. Whether you are using them as primary keys in PostgreSQL or as tracking tokens in a web app, the cryptographically secure randomness ensures zero predictable patterns in your output.

Cryptographically random UUID v4 using crypto.randomUUID()
Bulk generation: 1 to 1,000 UUIDs in one click
Format options: hyphens, uppercase, no hyphens
Copy individual UUIDs or the full batch as a newline-separated list

Frequently Asked Questions

What is the probability of a UUID collision?

UUID v4 has 122 random bits (6 are version/variant markers). For a 50% collision probability among a set of UUIDs, you would need approximately 2.7 × 10¹⁸ UUIDs - generating 1 billion per second for 86 years. In practice, the probability is negligible.

What is the difference between UUID v1, v4, and v7?

v1: based on timestamp + MAC address - sortable but reveals machine and time info. v4: fully random - the most common choice. v7: timestamp-ordered random (RFC 9562) - combines the sortability of v1 with the privacy of v4. Ideal for database primary keys.

Is UUID the same as GUID?

GUID (Globally Unique Identifier) is Microsoft's implementation of UUID. The format is identical; the terms are interchangeable. Windows/COM use "GUID"; web and cross-platform standards use "UUID".

Should I store UUIDs as strings or binary in a database?

Storing as binary (16 bytes) is more efficient than the 36-character string. MySQL/MariaDB have a BINARY(16) type for this. PostgreSQL has a native UUID type. Postgres is more storage-efficient than VARCHAR(36). Most ORMs handle both representations transparently.

Whether you need a single identifier for a quick fix or a list of a thousand for a load test, this UUID Generator provides instant, secure results. Bookmark this page for the next time you need a dependable online UUID generator.

UUID Generator online

Generate v4 UUIDs - cryptographically random, instant copy