Generate cryptographically secure UUID v4 values instantly — one at a time or in bulk. Copy-ready for databases, APIs, and applications.
A UUID (Universally Unique Identifier) is a 128-bit value used to uniquely identify records, objects, sessions, or transactions without a central authority. UUID v4 generates random identifiers with an astronomically low collision probability — making them safe to use as database primary keys, API tokens, file names, and session IDs.
Our UUID Generator uses the browser's crypto.getRandomValues() API for true cryptographic randomness. Generate one UUID or dozens in bulk.
UUID v4 is the most common UUID variant, generated from completely random data. It follows the format xxxxxxxx-xxxx-4xxx-yxxx-xxxxxxxxxxxx where 4 indicates version 4 and y is one of 8, 9, a, or b.
Extremely. With 2^122 possible UUID v4 values, generating 1 billion UUIDs per second for 85 years would give you less than a 50% chance of a single collision. For practical purposes, collisions are impossible.
UUID v4 is fully random and does not sort chronologically, which can hurt database index performance. UUID v7 (newer) is time-ordered and sorts naturally. For high-performance databases, v7 is increasingly preferred. For general use, v4 is universally supported.
All processing happens locally in your browser. We never see, store, or transmit your data. This tool is fully client-side and secure.
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