How big is a blog photo?

P1' s friend's work-69x46, with the image quality compressed to 9% and the size of 97K. How big is the photo on the blog? This is a problem. First of all, from the perspective of appreciation effect, it is definitely a photo with a larger size and higher image quality. I believe that photographers will also use this standard to set up digital cameras. So, just post the photos in the camera in the blog post as they are? If so, you will find that the upload speed is very slow, and even stop uploading or report an error. Because the photo is too big. Even if you can upload it successfully, netizens from all over the world will leave you a message because of various situations: "Why can't I open the photo!" To solve this problem, the usually conceivable way is to reduce the size of the photo. When the longest side is reduced to 8 or 6, the picture is changed from 3-4M to several hundred k, and the uploading speed is accelerated, and the opening speed of blog pages is also improved. However, on the other hand, the problem comes again, and friends will say, why isn't your photo clear? Not delicate enough, the artistic conception and charm didn't come out! In order to improve the quality of blog mapping, some friends offered suggestions, and the length of the film was reduced to 16 or 12. If the uploading data is still too large and the speed is too slow, the image quality will be reduced again, that is, 7% of the image quality will be selected when sorting out the pictures, and some people can accept 5%. This can also turn the photo into the size of several hundred k. You can add a small note when posting a blog post-click to see the big picture. In short, in order to upload successfully and improve browsing speed, you have to sacrifice the quality of some pictures. The question is: even if you have to agree to lose the quality of the picture, is it cost-effective to reduce the size? Or is it cost-effective to reduce the quality? What I mean by cost-effective here is that if it is also a 3K film, what kind of effect is better with a larger size and a smaller size? Two days ago, a careful friend made an experiment. Without his own consent, Shanren posted his picture here. Please see which compression method is better. Among them, the third and fourth pictures are compressed by the same digital image. Figure 3 is mainly about size reduction, and Figure 4 is mainly about image degradation. P2 friend's work-69x46, the picture quality is compressed to 9%, and the size is 88K. P3 friend's work-69x46, the picture quality is compressed to 9%, and the size is 94K.