You don't have to save it in WEB format, but you can also save it in JPEG format or GIF format. See what format the website allows you to upload. Files in Web and GIF formats are smaller and faster to browse than those in JPEG format.

The exported text is vague, probably because your quality has not improved. Of course, it is of high quality, and the file will be relatively large.

If it is a small picture, the way to make the text clear is to set the font size as large as possible, and the background color is quite different from the font color, which can make the font more obvious.