How Instagram handles image uploads
Instagram re-encodes every image you upload. It resizes to its own maximum dimensions — 1080px wide for square and portrait, 1350px for landscape — and compresses to a JPG quality that it controls. You cannot prevent this re-compression; it is part of Instagram's pipeline to keep its own storage and bandwidth costs down.
The consequence is that the quality of your final Instagram post depends not only on Instagram's compression, but also on the quality of the image you gave it. Uploading a heavily compressed image means Instagram compresses it twice, which compounds the artefacts.
What size should you upload
The ideal Instagram upload is:
- 1080-1350px on the long edge
- JPG format
- Around 500KB to 1MB
There is no benefit to uploading a 5MB image — Instagram will shrink it anyway. But there is a cost to uploading an image that is already visually degraded — Instagram will not restore quality it has lost.
Why compress before uploading
Three practical reasons:
- Faster upload. A 500KB image uploads quickly even on mobile data.
- Better final quality. You control the first compression instead of leaving it to your phone's auto-processor.
- Smaller phone storage. If you are preparing many photos, keeping them small saves space.
Format choice
JPG is the safest choice for Instagram. WebP is not universally supported by Instagram's servers yet, and PNG is unnecessarily large for photographs.
How FITLY helps
Set a target of 500KB, choose JPG, and FITLY will resize and compress your photo to fit. The result is a clean 1080-1350px JPG that Instagram will display at its best possible quality.