UUIDDev is a free tool and reference site for developers working with UUIDs. Everything runs in your browser — no account, no server-side generation, no logging of values you create.
What this site provides
Generator tools — UUID v7 and v4 generation using the browser’s native Web Crypto API. The UUID v7 generator produces time-sortable, RFC 9562-compliant identifiers with a monotonic counter for sub-millisecond ordering. The UUID v4 generator produces 122-bit cryptographically random identifiers.
Developer tools — the Tools section includes a UUID validator, a decoder that extracts version, variant, and timestamp from any UUID string, and a converter between standard string, hex, Base64, URN, and integer formats.
Guides — the Guides section covers UUID versions, database storage and index performance, security properties, and language-specific patterns for JavaScript, Python, and Go.
Glossary — the Glossary defines every term you will encounter when working with UUIDs: variant, namespace, collision, entropy, lexicographical order, and more.
News — the News section tracks changes to UUID standards, database releases, and library updates that affect how developers generate and store UUIDs.
Privacy and terms
- Privacy Policy — what data is collected, how analytics work, and why UUID values are never sent to our server
- Terms and Conditions — permitted use, disclaimer of warranties, and limitation of liability