Google used to clearly tell you which search results were ads and which were genuine: Ads had a clear orange background which real results did not. 

But a few years ago, they stopped doing this. Now, ads only have a tiny 'Ad' mark that's easy to overlook. It's obvious why: Google earn more money when it's difficult to tell the difference between genuine results and ads.

Enough! This extension hides the ads in your search results. You can see the ads by clicking the extension icon and 'Show ads'. When the ads are shown, they have a clear background color, similar to what Google used to do.

This app is open source. You can inspect its source code, flag bugs, or submit other feedback at https://github.com/ulyngs/open-source-remove-ads-from-google-search