Developer Guides

In-depth, source-checked articles for working developers. Each guide is reviewed against IETF RFCs, W3C/WHATWG specs, MDN Web Docs, and official project repositories before publication.

UUID v4 vs UUID v7 vs ULID: Choosing IDs for Production Systems (2026)
RFC 9562 added UUID v7 as a time-ordered alternative to v4. Here's when to use each format — including ULID and NanoID — for primary keys, distributed systems, and public-facing APIs.
Published 2026-04-08·9 min read·DevToolKit Editorial Team