The ERR_CONNECTION_CLOSED or “This site can’t be reached” can appear if you’re using Google Chrome or a Chrome-based web browser and there is an issue with the connection from your device to the website:

A sample of the error message on a domain indicating

To fix it, restart your modem/router to ensure the connection is working and your device is connected to the Internet. Next, reset your network Settings. Expand the section below to find the instructions according to your operating system:

Windows

For Windows 10 version 1607 and later, select the Start button, then go to Settings → Network & Internet → Status → Network reset
On the Network reset screen, select Reset now and click on Yes to confirm
Restart your device

Mac

Go to System Preferences → Network, select Wi-Fi, and click on the minus button to delete the current configuration
Click on the plus button and select Wi-Fi from the drop-down menu to set up a new connection

Linux

Open Terminal and enter the following command: sudo service network-manager restart

What to Do if the Issue Persists

There are some additional steps you can try:

If you’re using a VPN, disable it
Clear your browser’s cache
Flush your DNS cache
Use Google’s Public DNS
Disable your browser’s extensions
Update or reinstall your browser

Since this error is related to the device or connection, you can still verify that your website is working by using a different device as well as a different network. For example, on your mobile using data instead of Wi-Fi or through a proxy website, such as kproxy.com or proxysite.site.