What type of file format is commonly used for images on the web?

The JPEG file format is commonly used for images on the web due to its efficient compression algorithms, which allow for a significant reduction in file size without a substantial loss in quality. This makes JPEG ideal for photographs and images with intricate color variations, as it balances quality and file size effectively. Web developers favor using JPEG because it helps speed up page loading times, which is crucial for maintaining user engagement and improving user experience.

In contrast, while PDF is useful for documents and maintains the formatting across different platforms, it is not primarily intended for image display on websites. HTML is a markup language used for creating web pages, not an image file format. TXT files are plain text documents and do not support images or rich media content, making them unsuitable for web image representation.