The ressouce is locked

Specification of the HTTP status code 423

The 423 Locked status code means the source or destination resource of a method is locked. This response SHOULD contain an appropriate precondition or postcondition code, such as 'lock-token-submitted' or 'no-conflicting-lock'.

Source / Quote by: The 423 Locked HTTP Status Code is specified by section 11.3 of RFC4918.

How to throw a 423 statuscode with PHP?

To throw the HTTP status code 423 on a web page, the PHP function http_response_code can be used. The syntax is as follows: http_response_code(423) (PHP 5 >= 5.4.0, PHP 7, PHP 8)

Test the 423 HTTP status code

In order to be able to display the HTTP status code (in this case 423 Locked) 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:

Status code 423 Locked
URL: https://http-statuscode.com/errorCodeExample.php?code=423
Status: 423 Locked
Those: Network
IP address: XX.XX.XX.XX
Status code 423 Locked

How to create a custom error page for the 423 status code

Creating your own 423 Locked error page is relatively easy with the web server "Apache" as well as with the web server "NGINX".

Apache Webserver

The web server "Apache" is one of the most popular web servers on the Internet. To create an own 423 Locked error page in "Apache", the following change must be made in the following file.

File: .htaccess
ErrorDocument 423 /errors/423.html

NGINX Webserver

Similar to the web server "Apache", "NGINX" is also widely used on the Internet. To create your own 423 Locked error page in "NGINX", the following change must be made in the following file.

File: sites-enabled/default
error_page 423 /423.html;
location = /423.html {
    root /usr/share/nginx/html;

Browser compatibility of the 423 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

Constants in programming languages

Author: Tony Brüser
Author: Tony Brüser

Tony Brüser is an enthusiastic web developer with a penchant for HTTP status codes.