HTTP Error 503: Imagine someone searches for a topic and finds your website on page one of Google. However, when they click through to your website, their eyes land on a boring webpage that says “Service Not Available”.
What do you think they will do when they find your website on Google again? Chances are, they’ll skip it and hit the next link. When visitors search for answers and promise them the answers but can’t deliver them because something is wrong with your website, they lose trust in your brand.
Unfortunately, there is no Silver Bullet solution when a 503 Service Unavailable Error occurs on your website. You need to investigate what is actually causing the problem because although these types of errors indicate what happened to your website, they don’t tell you why it happened.
Read our guide to see what exactly the problem is and what solutions appear most frequently in order to fix your 503 Service Unavailable Error and not to lose potential customers.
What is a 503 error?
A 503 Service Unavailable Error is an HTTP response status code that indicates that your web server is working properly, but that a request cannot be currently processed. Since this is just a general error message, it is difficult to pinpoint the exact cause of the problem.
When a 503 Service Unavailable Error occurs on your website, visitors to your website land on an error page. Fortunately, there are five common solutions to troubleshooting most 503 Service Unavailable Errors.
How to fix an HTTP Error 503
- Restart your server.
- Check if your web server is being serviced.
- Correct incorrect firewall configurations.
- Search your server-side logs.
- Search your website code to find bugs.
1. Restart your server.
Sometimes the chain of servers hosting your website becomes overloaded. One of the most effective ways to open and update is to simply restart the web server. If your website is hosted on multiple servers, make sure to restart them all to get it back up and running.
2. Check that your web server is being maintained.
Most web servers shut down when they are serviced. If you can access your server’s administrative settings, review the configuration options to see when automatic maintenance sessions are scheduled. If you’d rather have full control over the maintenance of your server, you can also turn off these automatic updates in the configuration options.
3. Correct incorrect firewall configurations.
Your firewall is the gatekeeper of your website and protects your website from malicious visitors or distributed denial-of-service attacks (DDoS). Sometimes an incorrect firewall configuration causes your firewall to view requests from a content delivery network as an attack on your server and reject them, resulting in a 503 Service Unavailable Error. Check your firewall configuration to locate and fix the problem.
4. Search your server-side logs.
There are two types of server-side logs: application logs and server logs. Application logs replay the entire history of your website so you can see the web pages that visitors have requested and the servers they are connected to. Server logs provide information about the hardware your server is running on and details about its health and status. Search both types of server-side logs for alarming information about your server or website.
5. Search your website code for bugs.
If there is a bug in your website code, your web server may not be able to properly respond to requests from a content delivery network. Search your code for bugs or copy your code to a development machine. A thorough debug process is performed that simulates the exact situation in which your 503 Service Unavailable Error occurred and allows you to pinpoint the exact moment that an error occurred.
Anytime an error occurs on your website, it is important to fix it as soon as possible. If customers get bugs, they likely won’t come back to your page.
Editor’s Note: This post was originally published in January 2019 and has been updated for completeness.