For profile pictures, you can upload:

• JPG Images (e.g. with a name such as "picture.jpg") up to 1 MB in size
  
  
• Other Images (e.g. with a name such as "picture.gif" or "picture.png" or other types of image files) up to 50 KB in size.

If you upload a big image for your profile, even if it's within the size limits listed above, it might get 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 or animated images look funky.

For best results, please use a picture that is 170 x 170 pixels or smaller.