Unclear images in messages

All messaging apps (SMS, WhatsApp, Snapchat, etc.) use very low resolution.

The only way to transfer original resolution pictures is to use the Mail app, or share those pictures via iCloud, GoogleDrive, Dropbox, etc.).

Regards

Giulio

If you are sending an image to an android user then they may be receiving it in compressed and not the original image.

it could be that you have the "Low Quality Image Mode" set on. Go to Settings > Messages > scroll all the way down and you'll see "Low Quality Image Mode"....just be sure its toggled off.