How can I create a gif without losing any image quality

Question

So I have some pictures that i need to crop and save. I crop my images into circles and save them to .gif format so I don't have that white square around my image. when using GIMP, I just follow the default settings. my image before it is saved:

and after it is saved:

notice the difference in quality. I've read on the net that .gif doesn't support as many colors as it should. I tried to follow some advice, but they were directed more towards making animated gifs. I just want to keep the quality. I have looked at Poor Quality of the Image after exporting to .gif animation format and How can I export a flash file to a gif format without losing quality?, but like I said, they discuss animation. any advice?

Answer 1

GIFs only support up to 256 colours. This is why your quality is degrading. There is no way around this.

The format supports up to 8 bits per pixel for each image, allowing a single image to reference its own palette of up to 256 different colors chosen from the 24-bit RGB color space.

If all you need is transparency, consider a PNG (Portable Network Graphics) file. It supports a much wider palette and proper partial transparency (alpha channel).

PNG supports palette-based images (with palettes of 24-bit RGB or 32-bit RGBA colors), grayscale images (with or without alpha channel), and full-color non-palette-based RGB[A] images (with or without alpha channel). PNG was designed for transferring images on the Internet, not for professional-quality print graphics, and therefore does not support non-RGB color spaces such as CMYK.