I agree with a few answers, foremost Jake Robb’s. You are doing it wrong.
As Jake Robb said, modern web browsers are very complex. They need to deal with tons of media. Also, RAM has to take all of it. Your operating system, the browser, other applications, your antivirus software, the websites, the media… all of it gets loaded into RAM upon use.
Given, in a decent setup, Windows 7 alone would put at least 2GB of load on RAM, you are already half down as soon as you see your desktop. It gets even worse, if you use your onboard graphics card instead of a separate one. Because that one will use part of your RAM too. Meaning, if you like to play games and have set your shared onboard graphics card to 1GB shared memory, you are likely out of at least 3GB of RAM already.
Now comes the browser, which will likely put at least 300MB of load on your RAM without ANYTHING. And I mean, no extensions, no bookmarks, no additional tabs, no open website and Youtube videos… NOTHING! Take out your calculator. Because right now you are at like 3.3GB of RAM usage out of 4GB. You have 700MB left to play with. And we didn’t even talk about hundreds of MBs of bookmarks, extensions, websites, media, tabs…
But that is only if you don’t have any background applications, like for example your antivirus software, which with Windows is very important and necessary. My experience is, that my basic RAM load is more likely around 2.5GB and likely higher as soon as you start doing some stuff. And now it’s getting really uncomfortable within your limit of 4GB RAM.
Because if you now add like 50MB for each EMPTY tab you open, plus all the data from websites, like texts, images, animated gifs, videos… what a coincidence… your device is out of depth pretty quickly. 10 EMPTY tabs would put another approximately 500MB of load on your RAM!
Back in the day when there were only text websites and 56k modems, 4GB might have been enough. But these days, 4GB of RAM is quite little space for a heavy-weight operating system like Windows, plus modern browser and media-filled websites and what not.
So, as other people suggested, one option would be, to upgrade your RAM. Because once again I can confirm, what Jake Robb said. Even with a lightweight Linux distribution it’s not quite hard to run into the limits of my 8GB RAM on my notebook, INCLUDING SWAP! My PC has 16GB of RAM and that should be enough for average use. But as a power users, I would occasionally even run into the limits of that. So yes, Jake Robb is 100% spot-on on this.
But there is something between the lines here. The other option is, you decrease your load.
Switch to Linux instead of Windows, if you just use your browser and basic stuff. Not only does that remove the necessity of running antivirus software all the time. Also, adequate and beginner-friendly Linux distributions will put like 250 to 450MB of load on your RAM. Heck, even a heavy Linux distro with like 700MB to 1GB of basic RAM load would give you a lot more room to play with for your browser.
See, this is why every single PC user should at least know the hardware basics, like CPU, RAM, hard disk and graphics card. Because otherwise you can’t find a setup that suits your needs. You can’t put 10GB of RAM load on 4GB of RAM. If you use heavy applications and tons of them at the same time, you need an according device, that supports your working style and purpose. If you just check you emails and browse 3 eBay pages every other day, or maybe write an application every day, you might get away with 4GB of RAM. But obviously, that’s not what you do. As I said in the beginning, you are doing it wrong!
If you are interested in trying Linux, you might want to check this one out:
https://www.amazon.com/dp/B07ZCW8PVW
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If this answer was helpful for you, please don’t forget to upvote it on Quora: https://www.quora.com/Why-does-every-browser-constantly-run-out-of-memory-and-crash-with-4-GB-RAM-in-Windows-7-both-32-bit-and-64-bit-versions/answer/Chris-Bailey-364