Step #1: Copy the username of the Instagram profile which would you like to see bigger profile picture.
Example: the URL of the profile is https://www.instagram.com/realbarbarapalvin and username is realbarbarapalvin.
Step #2: Put the username of the Instagram profile into the input and then press the "Get Profile Picture" button, you can also hit enter.
Step #1: Follow steps above and get someones bigger profile picture.
Step #2: Saving full size profile image:
On computer: Right click to "See Full Image" then click "Save As" and save image to your computer.
On smartphones: Long press to profile image, press "Download Image" and save image to your smartphone.