CUID2 Generator — Secure, Collision-Resistant IDs for the Web
Generate CUID2 strings online — a modern, secure, collision-resistant ID format designed for horizontal scale and safe use in URLs, cookies, and databases. 100% local, no dependencies.
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Frequently Asked Questions
What is CUID2?
CUID2 is the successor to the original CUID, designed by Eric Elliott. It's a variable-length (default 25 chars), lowercase-only, URL-safe ID format that combines a timestamp, a per-process counter, a fingerprint, and cryptographic randomness. Widely adopted by Prisma and other ORMs.
Should I use CUID2 or UUID v7?
Both give you time-ordering and collision resistance. UUID v7 is standardized (RFC 9562) and understood by databases as a native UUID type; CUID2 is shorter, always lowercase, always URL-safe, and slightly more opinionated about entropy sources. Pick UUID v7 for interop with UUID-typed columns; pick CUID2 for cleaner-looking IDs in URLs.
Are CUID2s secure as authentication tokens?
No. The CUID2 spec is clear: CUID2 is a unique identifier, not a security token. Use a dedicated token generator (crypto.randomBytes → base64url) for anything involving authentication or authorization.
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