Awesome

CUID: Collision-resistant ids optimized for horizontal scaling and performance.

Implementation of https://github.com/ericelliott/cuid in Racket/Scheme.

A cuid is a portable and sequentially-ordered unique identifier designed for horizontal scalability and speed -- this version is ported from the reference implementation in Javascript.

Example

> (cuid)
"c0JU1BP7VK0000JENK2MF8ZMHN"
> (slug)
"LH0001EK8R"

Broken down

** c - 0JU1BP7VK - 0000 - JENK - 2MF8ZMHN **

The groups, in order, are:

c - identifies this as a cuid, and allows you to use it in html entity ids.
Timestamp
Counter - a single process might generate the same random string. The weaker the pseudo-random source, the higher the probability. That problem gets worse as processors get faster. The counter will roll over if the value gets too big.
Client fingerprint
Random (using cryptographically secure libraries where available).

Short URLs

Need a smaller ID? slug is for you. With 10 characters, slug is a great solution for short urls. They're good for things like URL slug disambiguation (i.e., example.com/some-post-title-<slug>) but absolutely not recommended for database unique IDs. Stick to the full cuid for database keys.

Awesome

CUID: Collision-resistant ids optimized for horizontal scaling and performance.

Broken down

Short URLs

License