How do you compress images in GIMP?

Answer 1

You can compress the pictures when they are saved, and the level of compression depends on the format you choose when saving the picture.

JPEG format has the best compression for photos. PNG and GIF formats are for simple titles, drawings, logos, etc.

Choose the format in the dialog box 'Save As' such as .JPEG, .PNG or .GIF in which you want to save the picture.

Also, in the "Save as .PNG" dialogue there is an option to modify the compression level which you can assign while saving.