HOW TO turn off internet access for a single browser tab

Web developers may occasionally have a need to test for scenarios when a web application doesn't have access to the internet. Rather than turn off access to internet completely, it is possible to selectively turn off internet access for a single browser tab just like muting audio playing within a web page.

In Chromium-based browsers, open Dev Tools (F12 keyboard shortcut) and within the Network tab change the setting to Offline in the dropdown as shown in the screenshot below.

This feature can also be used to conserve bandwidth for web pages that make numerous AJAX calls but can work even while offline.