If your business has a website, that website needs to be live and accessible at all hours. Server response codes can provide insight about what is generating errors, or causing the website to be inaccessible.
What Response Codes Are
For example, if someone wants to view the home page to your website, your machine (such as your phone, tablet, or laptop) talks to the server. The server responds with a code, such as 100 for Continue, until your device displays the home page in full. When the home page has finished loading, the server will respond with 200, or OK, to indicate that the request was successful.
Why Response Codes Matter
Response codes are informative — they tell you if a page is missing on your site, if the server is too slow to handle the amount of traffic it receives, or if a web application has a bug. The codes are often invisible to site visitors, but 404 pages (Not Found) are popular error pages, and those are based on the 404 code.
Common response codes include:
200 — OK: The web page loaded successfully.
301 — Moved: The web page has been moved permanently.
302 — Found: The web page has been moved to another URI (temporarily).
403 — Forbidden: The server will not display the page.
404 — Not Found: The request page could not be found.
500 — Internal Server Error: This is a generic server error message.
503 — Service Unavailable: The server is currently unavailable (due to traffic overload or down for maintenance).
For a more visual representation of server response codes, take a look at this infographic from 9gag.com that demonstrates the different types of errors with cats.
How You Can Use Response Codes
In the case of incorrect server configuration, or a website with bugs in the code, a server response code might be all that a site visitor sees. This is an indication that the server needs to be reconfigured, or the website needs to be updated.
A more benign and common response code is the 404 error. If a website displays that error when loading the page, that can often be easily resolved by either making sure there is a page where there should be a page, or by updating the link that points to that page.
Server response codes are part of every website. Your website administrator should be familiar with the most common codes to know how to address server issues that come up.