It seems backwards that a tiny 200×200 avatar would be harder to get looking sharp than a full-size banner image, but it genuinely is. There's less room for error, and every mistake gets magnified relative to how small the final image actually is.
Why avatars go blurry in the first place
The most common cause is shrinking an already-small or already-compressed image down even further. If your starting photo is 300×300px and slightly soft to begin with, resizing it to 150×150px won't add detail back — it'll just make the existing softness stand out more against the smaller canvas. Close behind that is upscaling: stretching a small photo up to meet some platform's minimum size requirement, which never actually creates detail that wasn't there to begin with.
Always resize down from the largest, sharpest version you have rather than a copy that's already been shrunk once before. Every resize introduces a small amount of softening on its own; doing it twice just compounds the problem. If all you have is a small source image, there's genuinely not much a resizer can do to recover detail that isn't there — that's a physics problem more than a software one.
Leave room around the subject before you crop
Most platforms display avatars as circles or rounded squares, which means the corners of your image get clipped off entirely. Faces and logos sitting near the edge of a square photo often end up partially cut once the platform applies its own mask. Crop with some breathing room around the subject before resizing down to the final size, not after.
Compression can be more aggressive here than you'd think
Because avatars are viewed small, you can generally push compression harder than you would on a full-size photo without anyone noticing — a 200×200px JPEG rarely needs to be more than 15–25 KB to look completely clean. If your thumbnail export is coming out at 100+ KB, the quality setting is probably higher than it needs to be for something displayed at that size.
Quick checklist, if you want one: start from your largest sharpest source image, crop with margin around the subject before resizing down, resize directly to the platform's exact required dimensions, and compress moderately since small images hide artifacts well anyway.
ImgReduce's dimension mode handles the resize step directly — lock the aspect ratio, set your target size, export.