Web Image Formats: Assessment of Their Real-World-Usage and Performance across Popular Web Browsers

TL;DR

This study evaluates the real-world usage and performance of various web image formats across popular browsers, revealing that newer formats like WEBP and AVIF significantly improve load times but are less commonly adopted.

Contribution

It provides a comprehensive analysis of image format preferences and performance impacts across browsers, highlighting the gap between format advantages and actual usage.

Findings

WEBP and AVIF reduce page load times by 21% and 15%.

JPEG and PNG remain dominant in web images.

WEBP usage is only 4% among popular formats.

Abstract

In 2023, images on the web make up 41% of transmitted data, significantly impacting the performance of web apps. Fortunately, image formats like WEBP and AVIF could offer advanced compression and faster page loading, but may face performance disparities across browsers. Therefore, we conducted performance evaluations on five major browsers - Chrome, Edge, Safari, Opera, and Firefox - while comparing four image formats. The results indicate that the newer formats exhibited notable performance enhancements across all browsers, leading to shorter loading times. Compared to the compressed JPEG format, WEBP and AVIF improved the Page Load Time by 21% and 15%, respectively. However, web scraping revealed that JPEG and PNG still dominate web image choices, with WEBP at 4% as the most used new format. Through the web scraping and web performance evaluation, this research serves to (1) explore image format preferences in web applications and analyze distribution and characteristics across frequently-visited sites in 2023 and (2) assess the performance impact of distinct web image formats on application load times across popular web browsers.