1. Sign with a black pen on plain white paper, larger than usual.
  2. Photograph it from directly above in daylight, or scan it at 300 DPI.
  3. Crop tightly around the ink so no paper edges or shadows remain.
  4. Drop it here. The preset resizes to 140×60 and lands between 10 and 20 KB, padding the file if the clean scan comes out smaller.

If your form asks for different pixels (UPSC uses 350×350, some state boards 300×80), use the Exact size mode on the reduce image size in KB page and keep the 20 KB cap and 10 KB minimum.

Try it on your own photoDrop a photo at the top of the page. Ten seconds later it's sized, sharpened and ready to post.
Compress a photo