Paper Title
Website Greenness Using a User-Centered Designed Extension

Abstract
The escalating energy consumption of data centers and the continuous growth of internet usage have brought the sustainability of websites into sharp focus. Carbon (CO2) emissions from online activities constitute a significant, yet often overlooked, portion of total greenhouse gases compared to traditional sectors like transportation. Therefore, the concept of a green website, which refers to optimized infrastructure, has become essential. To directly measure the websites, a browser extension was designed and implemented to independently gauge the energy consumption and CO2emission rates of web pages. The developed algorithm operates based on the total data size and the number of Hypertext Transfer Protocol (HTTP) requests, estimating each page's CO2 footprint by calculating the energy consumed during the loading process.The extension analyzes key indicators of optimized infrastructure, including page weight, background color, image format and dimensions, hosting type, the number of redirects, and the use of external scripts. This tool accounts for data size analysis, as well as the optimization of JavaScript and other influential factors. The developed extension successfully provided accurate and scalable data without compromising user privacy. Data were collected and analyzed from tests on 49 diverse, highly-trafficked websites to provide a comprehensive picture of website performance and sustainability.Our findings reveal that actions like data compression, reduced number of requests, and image optimization can improve infrastructure efficiency and significantly lower CO2 emission rate. The results clearly demonstrate that sustainable web design can not only mitigate environmental impacts but also enhance the quality of the user experience. Keywords - Green websites, Browser extension, Carbon footprint, Energy consumption, Performance indicators, Web sustainability