I Need Your Suggestions

Hello everyone. This is my first post in this forum. The last couple of days I am facing a problem with my computer. My computer has a bit less RAM, but I do a lot of work on the internet. The problem is that when I work on the Internet with a browser, a lot of primary memory is being used. Because of this, my computer is getting very slow. At present, I am using Firefox. Friends, can you tell me how to solve this problem? Any help will be appreciated.

Is it possible to buy memory?
What OS are you running?
Windows?
Linux? If so, which desktop?

How much ram does your computer have?
I hope that its 64 bit at least.
You need more than 900mb for what you want to do nowadays. And that might not be enough depending on what you do.

Use Icewm as a desktop environment.
Try palemoon or chromium.

Thanks for replying. I am using Linux Ubuntu, RAM 4GB. After searching online I found a solution from here. But my favorite browser is Firefox, not Opera.