Which still image file type is often used for photographs uploaded onto websites?

The .jpeg file type is commonly used for photographs uploaded onto websites due to its balance between image quality and file size. JPEG compression effectively reduces file sizes, making images load faster on webpages, which is crucial for providing a smooth user experience. This format also supports a range of colors and is widely compatible with various web browsers and platforms, making it the preferred choice for online photographs.

In contrast, other file types like .bmp are larger files that do not utilize compression, resulting in slower loading times. The .tiff format, while high-quality, is not as universally supported on the web, and .raw files are primarily used for professional photography and editing, as they contain unprocessed image data and are too large for web use. Thus, the .jpeg format's efficiency and widespread compatibility make it the ideal choice for online photography.