Burp Suite for Localhost

Testing a web app hosted locally with Burp Suite Community Edition.

Hosted app uses the same default port as Burp Suite. Change Burp Suite to use 8088 in Proxy/Option tab. Turn on invisible proxy option in Request Handling after editing the listener port in the Binding tab.

Chrome, IE, Edge

Even for Chrome, launch IE and click the Gear icon to get to Internet Options. In the Connections tab, click the LAN settings button. Check the proxy and set to the same IP and port used in Burp.

Firefox

In Tools/Options scroll down to Network Settings and click Settings… button.

Load the webapp in Firefox from the port you always use to access it (8080?)

You should see the intercepted request appear in Burp Proxy/Intercept tab, which are now highlighted, if you have Intercept in on clicked: