How do you test cross browser?

Question

Browsers

1. How do you test cross-browser compatibility?
2. What are the solutions for testing cross-browser compatibility of local sites?
3. Are there browser extensions?
Thank you.

Answer 1

Everything is www.browserstack.com

Answer 2

for IE I have only one IE9 virtual machine from the site https://www.modern.ie/ru-ru/virtualization-tools
For everything else, native modern browsers. (it makes no sense to test somewhere else, because this will make development more expensive (I mean fixing possible bugs))

Answer 3

Perhaps the more developers will score on cross-browser compatibility, the faster the creators of browsers will come to some kind of unified standard and all this ugly mess of dozens of browsers will disappear.

Answer 4

For browsers with >15% of the audience of the service - only live browsers, if necessary - virtual machines.
For the rest, a browser stack will do.

Answer 5

I'm ashamed, but yes, a bunch of installed browsers.