Universal Stylus Initiative

The Universal Stylus Initiative (USI) is a non-profit alliance of companies promoting a technical standard for interoperable active pen styluses on touchscreen devices such as phones, tablets, and computers.

It defines a two-way communication protocol between the stylus and the computer and allows the stylus to remember user preferences for ink color and stroke. It support 9-axis inertial measurement.

Products started coming to market in 2019 including one stylus and several Chromebooks from different manufacturers. By 2019, there were over 30 members, including Google and 3M, but some major players like Apple and Microsoft had not joined. As of 2022, the promoters include Google, Intel, Lenovo, Samsung, and Synaptics. Dell, Sharp, and Wacom are contributors.

While USI promotes itself as an open standard, access to detailed specifications is restricted to paying members.