HTTP status codes, the 4xx and 5xx variants, appear when an error occurs while loading a web page. These are standard error types, so you can see them in any browser, such as Edge, Firefox, Chrome, Opera, etc.
HTTP Status Codes Explained in 5 Minutes
Below you will find the most common HTTP status codes 4xx and 5xx, with helpful tips on how to bypass them and get to the web page you were looking for.
Codes starting with 1, 2, and 3 are not errors and are usually not seen. More information about this can be found here: A complete list of HTTP status lines.