Yes, OS Adder is free to use. It is available as a free plugin on WordPress.org.

How many websites use OS Adder?

OS Adder has 10 active installations as tracked by WordPress.org.

What are the best OS Adder alternatives?

Popular alternatives to OS Adder include WPCode – Insert Headers and Footers +…, Code Snippets, Simple Custom CSS Plugin. You can compare them side-by-side on our comparison pages.

Does OS Adder work with the latest WordPress?

OS Adder has been tested up to WordPress 4.3.34. It requires WordPress 3.0.1+ and PHP false+.

PluginSift

OS Adder

Name: OS Adder
Author: trauben-nuss

Add the operating-system's abbreviation as a CSS-Class to the body-tag.

By trauben-nuss·CSS·Free

·10 active installs·Updated 10 years ago

Download Compare

As of April 2026, OS Adder is a WordPress css plugin with 10 active installations and a 0/5 rating0. It has been downloaded 1.5K+ times in total. Requires WordPress 3.0.1+ and PHP false+. Available on WordPress.org since 2013. Last updated 10 years ago — may have compatibility concerns. Top alternative: WPCode – Insert Headers and Footers +….

0/5Rating

10active installs

1.5K+total downloads

13 yearssince 2013

Overview

This plugin adds a abbreviation of the operating system (win, mac, linux, iPad, iPhone) to the body-tag.
So if there’s a OS-specific difference, you can easily react to it by using the css-selector (e.g. “.mac”).

Next steps of this plugin:
* adding a settings page
* add the class to specified elements
* add user-language-abbreviation to specified elements

let me know, if you wish something helpful.

Read full description on WordPress.org