To make your GIF as efficient as possible:
Crop any extra space around the image. Reducing the pixel dimensions of an image is the most effective way to reduce the file size. If you use Photoshop, the Trim command works well for this.
When you prepare a GIF image, reduce the output dimensions. Each graphics-editing program offers different commands for resizing.
Reduce the number of colors in the image. GIFs only display 256 colors, but if your image only has a few, then reduce the color count anyway. When reducing colors in GIFs, you get the best compression when the number of colors is set to the smallest possible of these options: 2, 4, 8, 16, 32, 64, 128, or 256.
Reduce the number of frames in the image for animated GIFs. Avoid useless animation, in general. Excessive animation adds to web page download time, and many people find it distracting.
If you use Photoshop, create a GIF file by using the Export As menu item. Select File > Export As. When the menu opens, select GIF as the file format and reduce the physical dimensions (width and height) of the image.
If you use Adobe Photoshop Elements, select File > Save For Web. This process opens the Save For Web dialog box that is also found in Adobe Photoshop at File > Export > Save for Web (Legacy). When it opens, apply dithering, reduce the color, and modify the physical dimensions of the image.
Avoid dithering. Dithering may make some images look better, but it increases the file size. If your software allows it, use a lower level of dithering to save extra bytes.
Some software has a lossy option for saving GIFs. This option can significantly reduce the file size, but it also reduces image quality.
Don’t use interlacing. Interlacing usually increases the file size.
Both Photoshop and Photoshop Elements show the download time. Pay no attention to it. It is based on the use of a 56k modem. A more valid number appears if you select a cable modem from the drop-down menu.
