Keeping text readable
Text suffers first when a JPEG is squeezed hard: edges blur and small print smears. For a document, fewer pixels at a good quality usually reads better than the full size at the lowest quality. A long edge of about 1,500 to 2,000 pixels keeps an A4 page legible for most forms.
Crop the empty space around the page first. ToolGPT's crop card draws each shape on your own image, and the custom crop box lets you drag to the exact edges of the document.