osu! difficulty filter is a Chrome add-on developed by tboombringer. As an extension for the popular rhythm game osu!, this tool allows users to filter beatmaps based on their star difficulty. With the help of sliders or text inputs, you can enter a desired difficulty range, and the extension will hide any beatmaps that fall outside of that range.

To utilize the osu! difficulty filter, you will need a registered osu! API key. Once you have obtained this key, you can easily apply the filter to your beatmap listings. By using the "stars>/<=(=)" search term, you can effectively narrow down the beatmaps based on their difficulty level.

This add-on is a valuable resource for osu! players who want to focus on beatmaps that match their skill level. With the osu! difficulty filter, you can easily find beatmaps that provide the right amount of challenge, helping you improve your gameplay experience.