HOW TO UPLOAD TO INSTAGRAM WITHOUT LOSING IMAGE QUALITY
I’ve managed to compile some reasons as to why Instagram might be reducing the image quality on your posts.
ONE of which is that you are not following Instagram’s max resolution guidelines, which is currently set at 1080 x 1350px. Any image that is greater than the said resolution will be made smaller by Instagram and thus may affect the quality of the image.
Secondly, it also depends on the format of the image that you are using. Instagram’s default format for images is JPEG (.jpg), meaning that any image that is uploaded in PNG (.png), BITMAP (.bmp), or anything other than JPEG, will be converted to JPEG and as such loses some of the quality during the conversion.
When you consider the number of images that are being uploaded to Instagram every single day and the server power that is needed to run the platform, you’ll soon forgive Instagram for reducing file sizes where possible. Try to keep your image file size to a minimum (without affecting image quality) to avoid having it be poorly compressed by Instagram.
Last but not least, Instagram is predominantly a mobile-based app, and as such PRIORITIZES uploads from mobile (or tablet) devices when it comes to quality.