I've run out of data on my mobile (Wi-Fi is not available all the time). However, I still want to search for websites where the important part of the content is only on the plain HTML (for example: blogs, press...).
I just want a browser that only asks the servers of these websites for plain HTML and removes all the images/videos/javascript before starting to ask for these contents too. I cannot find anything about this on the internet. Is this possible?
You can accomplish what you want using the Firefox web browser with the uBlock Origin extension.
Simply configure uBlock Origin to block all scripts, images, and remote fonts.
You can also configure it to block all "large" media elements, and define exactly what you consider to be "large".
Using these techniques, the amount of data you use will decrease dramatically.
Both of these software packages are fully open-source and free of charge (gratis).
If you are on Linux, you could use links. On the right column of that page you will have some similar packages listed, such as lynx.
