Google PageSpeed Insights can degrade image quality

I'm really very tired of being a slave of Google dictations about what is a good site and what is good content. However, there is no way to deny that most sites depend on Google search engine results to become known to computer and mobile users.

Anyway, Google gets more and more arrogant as time goes. Since some time ago, they have a tool called "PageSpeed Insights". Despite the name makes it seem like an advisory report generator, probably someday, if a site doesn't reach good results, it can be penalized in search engine. It already happened with their tool to test if a site is "mobile friendly". From advisory to slavery. They really decided to dictate what is good or bad in internet. Let the user choose is not good enough for them.

I don't like Google playing God, but the situation becomes unbearable when they make things with wrong premises or technical flaws. Their PageSpeed Insights tests any site page and can give you the "right answer", so you can get a good score. In other words, this tool lets you download the optimized resources from the tested page, so you can use them "as they should be" to deliver a fast page.

In the Picture to People case, for most JPG images, the only way to make PageSpeed Insights satisfied about the images size is using the images it "optimizes" by itself. I have made many tests and no "non-destructive" optimization was good enough to PageSpeed Insights.

PageSpeed Insights decreased the JPG quality of my images (increasing the lossy compression rate), but usually it's negligible just for regular (high entropy) photos. For my JPG images that are not regular photos, Google "dummy optimization" generated visible graphic artifacts (noise), degrading visual quality. Saving these images as PNG files is not an option, because JPG format generates much smaller files, even when using a small (non visible) quality loss as I made to publish them at the site.

Saying it another way, many Picture to People pages will just get a high score from PageSpeed Insights if I use poor quality images. It's not reasonable and Google should immediately fix this. They can optimize images as they want, but they NEVER can decrease original image quality based on general naive assumptions. It can just create a poorer and uglier web.

Below I show you three examples. First you see the original image, after the same image visually corrupted by PageSpeed Insights (click an image to see it full-size). Maybe the problem is not strong in your monitor, but it can be annoying in many ones.

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