In yesterday’s post, I covered some of the web server status codes in the 1xx, 2xx, and 3xx ranges.  As a recap, here’s what the various ranges generally indicate:









Client Error


Server Error


400 Range Status Codes

Most of the 400 range status codes give verbose feedback in your browser, meaning they tell you straight up what’s wrong.  The first example of this is the 401 status.  This is when the client (you) tries to access something they’re not allowed to, otherwise known as “Unauthorized Access.”  This is what a typical Unauthorized status message looks like in Google Chrome:

That status is very intrusive.  It disrupts the user experience and is actually a great idea to fix it.  This is the JadeServe 401 status page, that still gives access to the menu and creates a seamless experience:

Another common 4xx range status is 403.  This is USUALLY because you tried to view a directory on a web server that doesn’t have a default index file in it.  In Google Chrome, this looks like:

Again, like the 401 status, this is very intrusive and no one likes that.  It’s best to fix this to another custom error page so your users have the absolute best experience.

The most famous of all status codes is the infamous 404 – File Not Found.  Nine times out of 10, it’s because someone typed the URL wrong.  The rest of the times is because of stray, forgotten links on your site.  If you have a lot of 404 errors, you should definitely look into the cause of them.  This is another error message that you can mask with a custom page, so your users aren’t distracted by them, and with a custom page, you can include error logging, and be informed whenever the errors arise.  This will help troubleshoot issues with your site and make your users happier in the long run.

Not a common status code, but notable is code 418.  This is an official status code for “controlling, monitoring, and diagnosing coffee pots.”  This is a true status that was officially put into place April 1, 1998, and is officially, thoroughly, documented in RFC 2324, and is worth a read.

The final 4xx error that will be discussed today is 451.  This is a special error code that means the selected resource was pulled down for legal reasons, including national security, copyright infringement, privacy laws, or by court order.  If you come across this error, you should probably leave the site post haste.  As a small bit of trivia, this error code actually received its name from the banned book Fahrenheit 451.

500 Range Status Codes

This range of status codes is reserved for server and misconfiguration errors. 500 is literally for “Internal Server Error.”  This is usually for coding errors.  This is a verbose error that generally looks like:

Like this says, you can find out more in your server logs about precisely what the error is from.  If you notice your server logs are getting large, it’s something that should be looked into.

The final status code that we’re going to discuss if 503.  This means that the server is overloaded or down for maintenance.  If you see this error, you may want to look into code optimization, hardware upgrades, or see if the maintenance flag was set on the server accidentally.


These status codes are tools to help diagnose and fine tune your website for the best possible user experience.  All of these status codes can be diagnosed and corrected by JadeServe.  When the server runs well, your business runs well.

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