The ニコ生コメントサイズ調整 is a free add-on for Chrome that allows users to customize the text size of comments in the Niconico Live streaming platform. This tool specifically adjusts the size of comments in the right-side comment section, enabling users to set the text size anywhere from 50% to 300% of the default size, enhancing readability based on personal preferences.

To utilize the features, users can click on the "Aa" icon located next to the player settings in Niconico. This action opens a settings window where adjustments to both comment size and comment number size can be made. Changes are applied in real-time using a slider, and users can also fine-tune adjustments with the mouse wheel. A double-click on the slider resets the size to the default position of 100%.