Instagram is not just a photo editing app. It also allows you to share your photos and videos with friend, family and Instagram followers. It is a fast and fun way to share your photos with family and friends. If you are using Apple iOS device, then you can not to save filtered photos before sharing them.
Once you upload the photo to Instagram and choose to save filtered photos to your phone, then the high-resolution versions of your Instagram photos will be saved on your phone. Instagram allows you to save the photo to your phone in the highest resolution size possible. The maximum resolution on iOS device is 2048 x 2048.