521
Web Server Is Down
Specification of the HTTP status code 521
How to throw a 521 statuscode with PHP?
To throw the HTTP status code 521 on a web page, the PHP function http_response_code can be used. The syntax is as follows: http_response_code(521) (PHP 5 >= 5.4.0, PHP 7, PHP 8)
Test the 521 HTTP status code
In order to be able to display the HTTP status code (in this case 521 Web Server Is Down) and other information on the client side, the development console must be opened with F12. Afterwards you have to navigate to the tab "Network". Now you can open the page, in the network tab you should see the web page (example index.php). This must be selected and then the Herder section must be selected. Here the user will see the following result:
URL: https://http-statuscode.com/errorCodeExample.php?code=521
Status: 521 Web Server Is Down
Those: Network
IP address: XX.XX.XX.XX
Browser compatibility of the 521 status code
| Chrome | no data |
| Edge | no data |
| Firefox | no data |
| Opera | no data |
| Safari | no data |
| Chrome Android | no data |
| Firefox for Android | no data |
| Opera Android | no data |
| Safari on iOS | no data |
| Internet | no data |
| WebView Android | no data |
