1. A website optimization system comprising at least one server with one or more processors and non-transitory computer-readable memory, the website optimization system performing a computer-implemented method for automatically assessing whether visual elements of a website increase or decrease the website's credibility, the computer-implemented method comprising: classifying each website of a plurality of websites based on subject matter of the website; identifying a group of credible websites from a set of the plurality of websites that are similarly classified; determining a common set of visual elements presented in each credible website of the group of credible websites; scanning visual elements present on a new website that is not in the group of credible websites and that is similarly classified as the group of credible websites; computing a credibility score for the new website based on comparison of a particular visual element present on the new website that is also present in the common set of visual elements; and presenting the credibility score in conjunction with presentation of the particular visual element of the new website.