- Be sure that all images are sized correctly for their purpose.
- Always resize images in an image-editing program in their original format.
- Set the resolution to 72 dpi. Higher resolution will not provide a sharper picture, just a larger file.
- Provide an ALT tag for all photos.
- Include the credit information for all photos.
- Select the correct file type for maximum optimization:
a. Photos – .PNG, .JPG (.JPEG), or .GIF
b. Images – PNG, .JPG (.JPEG), or .GIF
- GIFs are best for flat color images with no gradients.
- GIFs provide the lowest file size for images that have flat colors and no blends. They can also have transparent backgrounds.
- Photos can be saved as either PNGs or JPEGs. PNG photos tend to have larger file sizes than JPEG photos.
- There are three (3) types of PNG formats: PNG 8, PNG 24, and PNG 32. PNG 32 is the format for transparency and will sometimes yield a higher file size than PNG 8 or PNG 24.
- PNG 32 offers the best option for any images requiring a transparent background.