Profile images are sometimes compressed to fit better and load more quickly. This compression usually just makes your image look smaller, but it can sometimes make images with transparent backgrounds look funky. In the compressed version, the transparent background may appear black...

If you want to use an image with a transparent background, your best bet is to try to avoid any compression:

• Make sure your image is smaller than 50kb
• Make sure your image is smaller than 170 x 170 pixels
• Then try reuploading it.

Otherwise, if you have a program for editing images:

• Give your image a solid background color
• Then try reuploading it.