Instagram shows feed images at 1080 pixels wide. Uploading exactly that width avoids Instagram’s own re-compression of very large photos. The width is preset to 1080 px and the aspect ratio is kept, so nothing is stretched.
How to do it
Add your photos.
Width is set to 1080 px with the aspect ratio kept — change it for stories (1080 × 1920).
Process and download.
Frequently asked questions
What sizes does Instagram use?
Square 1080 × 1080, portrait 1080 × 1350 and stories/reels 1080 × 1920. Crop to the shape you want first if your photo has a different ratio.
Will resizing reduce quality?
Making a photo smaller keeps it sharp. The output quality can be adjusted before processing.