The file format commonly used for compressing images without losing quality is PNG (Portable Network Graphics). PNG uses lossless compression, meaning that it retains all original image data while significantly reducing file size, making it ideal for web graphics and images with transparency. Unlike JPEG, which sacrifices quality for smaller file sizes, PNG maintains clarity and detail, making it suitable for images requiring high fidelity, such as logos, icons, and illustrations. This format has become a standard choice for web designers and developers.