Do you want to easily change proxy setting from the top panel? If you are using GNOME Shell, then Proxy Switcher by flannable is the right extension for you. This allows you to do single click to change either using a proxy or no proxy for the whole system. It is basically same with changing proxy settings manually in GNOME System Settings, but Proxy Switcher makes it easier.
Follow our instructions about installing GNOME Shell extension. One installed, Proxy Switcher will be a new entry on the top panel tray.
Actually, GNOME already has good feature to set the proxy connection up. It supports HTTP, HTTPS, FTP, and SOCKS proxy. It is available via GNOME System Settings > Network Settings. But this default GNOME feature has no handy feature to change proxy settings quickly. So Proxy Switcher extension gives what it is missing. In these examples, I am in Indonesia with the IP address 126.96.36.199 and I try to change my IP into another country by using proxy.
(1) SOCKS example: Proxy Switcher is very good approach to use with SSH tunneling in local SOCKS proxy. To use it, just create a tunnel to a remote SSH server by openssh (see our easy SSH Tunneling tutorial) in the 127.0.0.1:1080 local address. Then set your GNOME Network Settings for SOCKS field into 127.0.0.1:1080 like picture below. Click Apply System Wide button and enter your password. Then fire up your web browser and check whether your IP address is changed or not. Here, I try a France SSH server to tunnel into and my IP address changed.
(2) HTTP example: using HTTP proxy is basically the same as SOCKS proxy. Just add the IP address:port information into the HTTP field in the Network Settings. I try to use a free proxy from incloack.com and here is the result.
If you are trying to use many free proxy addresses like in incloak.com, remember that not all of them work properly. Some of them work slowly or even don't work at all. So first disable any proxy extension installed in your web browser, then get ready to recheck every new proxy you entered by using "what is my ip" keywords in a search engine. Happy trying.