When you open any web page inside Google Chrome, it connects to the Internet, fetches the latest version of the page from the server and displays it on your screen. If your computer is offline, Chrome will display an error message with a dinosaur* image saying it is unable to connect to the Internet.Google Chrome Offline
[*] This is the Tyrannosaurus rex (or T-rex) dinosaur that had tiny little arms and the image probably illustrates that Chrome, like the dinosaur, couldn’t reach the Internet because of its short arms. (source: Quora) Web browsers like Internet Explorer and Firefox offer an offline mode that auto-saves a copy of web pages as you browse the Internet and displays this local copy when you are not connected to the Internet. Thus, if you are taking a flight, you can open all the web pages that you’d like to read later, close the browser and the pages will still be available for reading while your computer is offline.
Google Chrome doesn’t offer an offline mode by default but Addy Osmani shares a hidden setting that will bring the offline feature to your browser.

Offline Browsing inside Google Chrome

While inside Chrome, type chrome://flags/#enable-offline-mode in the address bar, click “Enable” and restart your browser. Your Chrome will no longer serve the “not connected to the Internet” error if the page you are trying to access is available in the local cache.
Google Chrome caches the HTML content, images, JavaScript and the CSS stylesheets associated with a page so your offline copy should not look very different from the original. However, if there are resources that require an active Internet connection, like JavaScript widgets or videos, they’ll be replaced with placeholder images.

To test the feature, open any page inside Chrome, turn off your Wi-Fi or disconnect the Ethernet cable, and restart the browser. If the offline mode is enabled, the cached version would show up on your screen.