How to Generate UUIDs Online for Free
Universally Unique Identifiers (UUIDs) are 128-bit numbers used to uniquely identify information in computer systems without central coordination. Whether you need a random UUID for database primary keys, session identifiers, or unique resource names, you can generate them instantly online. This guide shows you how to generate UUIDs using fixie.tools — completely free, no signup, supporting multiple UUID versions.
Step 1: Open the UUID Generator
Visit fixie.tools/uuid in your web browser. The tool runs entirely client-side in your browser, meaning UUIDs are generated locally with no server communication. No account creation or signup is required, and it works on all devices including desktop, tablet, and mobile.
Step 2: Select UUID Version
Choose the UUID version that matches your use case. Version 4 generates random UUIDs and is the most commonly used for general purposes like database IDs or session tokens. Version 1 generates UUIDs based on timestamp and MAC address, useful when you need time-ordered identifiers. Version 5 generates UUIDs from a namespace and name using SHA-1 hashing, ideal for creating deterministic UUIDs from existing data. Most applications use Version 4 for its simplicity and randomness.
Step 3: Configure Generation Options
Decide how many UUIDs you need to generate. For single UUIDs, the default works perfectly. For bulk generation, specify the quantity (up to 1000 at once) to generate multiple UUIDs simultaneously. You can also choose the output format: standard hyphenated format (e.g., 550e8400-e29b-41d4-a716-446655440000), compact format without hyphens, or uppercase variants. For Version 5 UUIDs, enter a namespace UUID and a name string to generate a deterministic UUID.
Step 4: Generate UUIDs
Click the 'Generate' button to create your UUIDs instantly. The tool generates cryptographically strong random UUIDs (for v4) that conform to RFC 4122 standards. For bulk generation, all UUIDs appear in a text area ready for copying. Each UUID is guaranteed to be unique with effectively zero probability of collision across all systems and time.
Step 5: Copy and Use Your UUIDs
Click the copy button to copy individual UUIDs or the entire list to your clipboard. You can paste UUIDs directly into your code, database, configuration files, or anywhere you need unique identifiers. UUIDs are generated entirely in your browser, so there's no privacy concern and no server-side logging. Generate as many as you need — the tool is completely free with no limits.