WebP vs. JPG: Which is better?

[lovasik]

I apologize, but I've observed something rather peculiar.

Isn't it generally understood that WebP images are superior to JPGs in terms of speed, lightness, smaller file size, and overall efficiency?

However, I frequently encounter the opposite scenario. I'll have two instances of the exact same image, with identical dimensions, yet the WebP version is significantly larger in file size than the JPG!

This completely contradicts my understanding and preconceived notions about this.

All the blogs, advice, and videos consistently point towards the modern web embracing WebP due to its supposed advantages – speed, lightweight nature, and reduced file size.

So, what exactly is going on in my case?

[cday]

Are you able to post the same image saved as JPEG and WebP for detailed examination?

[lovasik]

Invalid file extension: image.webp

The forum here does not support this extension.

[Kadet]

Invalid file extension: image.webp

The forum here does not support this extension.

Pack all images to zip file.

The question is, what do you want to use pictures for?

I did a lot to compare whether it is a lossless packing or lossy. Webp files were always smaller than JPG, with comparable quality. Here, however, It is true to a lossy compression, where I use in JPG packed color in as 420. Webp has this powerful defect, that he cannot cod color as 444, which JPG can do. So if you want to create high quality images, but with loss coding, JPG wins, despite larger files. With lossless compression, Webp always wins.
But now, in mid 2025, it is neither Webp nor JPG. If you want to upload heavily packed pictures on your website, you will choose the AVIF format that has 420 and 444 color coding. If you want to have good quality pictures in your home collection, but better compressed than JPG, then you choose the JXL format (format designed to replace JPG, Web, PNG, GIF and other formats).

You will not get a smaller file if the source image is already very compressed. Such that files should be first uploaded to AI, such as Topaz Photo AI, to improve quality, and then compress it with a modern codec.

[lovasik]

RAR:

xnview.rar

image Y.jpg

This is just a simple example of an image that is only 500 pixels wide.

[Kadet]

It is as I suspected. The JPG file is very compressed, with this all typical JPG artifacts. 27 KB WEBP is a copy of JPG file. I can compress this JPG to WEBP file to 15 KB and the quality will not be very different from this 27 KB, and seemingly even it can be better, because it will reduce some JPG artifacts.
For me these images are too much compressed.