For performance, load, and stress-test for web servers, we are using free tool called Webserver Stress Tool.
Webserver Stress Tool is a powerful HTTP-client/server test application designed to pinpoint critical performance issues in your web site or web server that may prevent optimal experience for your site’s visitors.

Please follow below procedure:
    • Click on download tab in main menu bar.

 

    • after click on download tab download tool and extract that.

 

    • click on install

 

    • after install you getting below screen.

 

You can increase no of user and no of click.