u64in is a free Chrome add-on developed by phoenix911. It falls under the category of Browsers and specifically the subcategory of Add-ons & Tools. This program allows users to easily compress and share any URL between their computer and mobile devices.

The name u64in is derived from "u64," which stands for unsigned 64-bit integer, the maximum size possible to code in C programming. With u64in, users can quickly and conveniently compress any URL into a easily sharable format, such as a QR code or an 8-character link.

This add-on provides a simple and efficient way to share URLs without the need for lengthy and complex links. Whether you want to share a webpage, article, or any other online content, u64in makes it easy to generate a compact link that can be easily shared with others.

With u64in, sharing URLs between your computer and mobile devices has never been easier.