HTTP error 503: What it is and how to fix it
Key takeaways
- HTTP error 503 is a server-side issue that causes a website’s unavailability.
- Causes of 503 error include server overload, maintenance, DNS issues, and DDoS attacks.
- Learning more about troubleshooting HTTP errors can help prevent website downtime.
It’s frustrating to expect a website to load but see a 503 Service Unavailable error message instead. This common server-side error affects both end-users and website owners. For end users, this means more waiting. For website owners, this means lost potential web visits.
But what does HTTP error 503 mean? Why does it occur? In this guide, we’ll break down its causes and what you can do to resolve it.
What is HTTP error 503
The HTTP error 503, or ‘503 Service Unavailable,’ suggests that the website is temporarily unable to handle requests, either due to too much traffic or ongoing maintenance. While the website may still be ‘online,’ it can’t serve pages at the moment. For website owners, this can lead to lost traffic and potential revenue.
Error variations
There are various ways that you may encounter a 503 error.
- 503 Service Unavailable
- 503 Service Temporary Unavailable
- HTTP Server Error 503
- HTTP Error 503
- Error 503 Service Unavailable
- The server is temporarily unable to service your request due to maintenance downtime or capacity problems. Please try again later.
Sometimes, servers also send a Retry-After header. This header gives the end-users an estimated time how long they should wait to reload the page again.
Why does the 503 error occur?
There are many reasons why a 503 error occurs. However, the main common causes of the error include:
- There are too many website visitors.
- The site is going through maintenance.
- Hackers are hijacking the site and flooding it with traffic.
Other causes include misconfigured Firewalls and DNS settings, problematic plugins, and internet connection.
How to fix and prevent HTTP error 503
Fixing HTTP error 503 quickly is important, especially for website owners. Aside from causing hassle to web visitors, this can also affect your site’s search engine ranking.
If your site is frequently unavailable due to errors like HTTP 503, search engines like Google may eventually remove your page from their index. However, since this error has multiple causes, there isn’t a one-size-fits-all solution. So, we’ve listed below several troubleshooting steps you can consider.
1. Schedule maintenance
This first one is more of a preventive measure than an immediate fix. Make sure to set routine maintenance during off-peak hours. This way, you can minimize disrupting high traffic and know when to expect website updates. We recommend you use a maintenance mode page to tell users about the site’s ongoing update.
2. Fix firewall configurations
Firewalls are important for network security. But sometimes, overly strict firewall settings can mistakenly block legitimate traffic. If this is the case, review your firewall rules and try turning off unnecessary services on the firewall. Ensure that real users and search engine bots can access your site.
For TrueShield Firewall users, see this article for a step-by-step guide on how to configure your firewall.
3. Fix DNS issues
Another step you can take is by fixing your Domain Name System (DNS) settings. The DNS is like the Internet’s address book, translating domain names into their corresponding IP addresses. So, if there’s a misconfiguration in the DNS, users can’t reach your site.
Check your DNS settings and ensure your domain points to the correct IP address. Check out this detailed tutorial on managing your DNS settings in your Domain.com dashboard.
If you’ve recently changed your hosting provider, allow time for DNS propagation.
4. Disable your content delivery network
Websites often use a content delivery network (CDN) to enhance their performance, especially when handling a high traffic volume. But sometimes, even CDN can cause the error 503 to occur. So, if your website uses CDN, consider temporarily deactivating it.
5. Disable your plugins
If you’re running a WordPress website, consider the possibility that conflicts with WordPress plugins can cause the HTTP error 503.
To test this, temporarily disable your WordPress plugins through your server’s control panel. Then, reactivate them one by one. This process can help you identify whether or not a plugin is causing the error. See this detailed instruction on how you can disable your WordPress plugin.
If plugins aren’t the issue, you can try the next steps.
6. Configure your IIS settings
If you’re running an Internet Information Services (IIS) website, ensure it’s running under the correct application pool. You can check the IIS Manager through your local Control Panel. If the pool has stopped, restart it.
You can also review the event log for errors. Through the Event Viewer, navigate the System or Application logs and look for an application pool identity error. If there is, updating its credentials may help.
Check this tutorial by 4sysops, an online community of IT professionals, for detailed information on troubleshooting this issue.
7. Upgrade your server resources
If HTTP error 503 persists after every attempt to fix it, the problem could be caused by your server’s resources, including bandwidth and storage limitations. So, consider upgrading your plan.
However, before you make a decision, consider contacting your hosting provider’s support team first. Inform them of the steps you’ve taken to fix the error. This way, they can provide you with further help, whether it’s troubleshooting or buying a new hosting plan.
How can end-users fix error 503
While the HTTP error 503 is a web server’s fault, end-users can still take a few steps to access the site again. Here are a few tips.
1. Refresh the page
The HTTP error 503 is temporary and sometimes happens only for a brief moment. Consider refreshing the site and check if it’s back online.
2. Check your internet connection
Sometimes, an unstable connection can prevent the pages from loading. Make sure your internet is working. To do this, check out other websites. If they’re also unable to load, there might be something wrong with your internet connection.
3. Clear browser cache
Web browsers store website data to speed up loading time. Unfortunately, these data can sometimes be corrupted and outdated, especially when a website goes through an update. This may not always be the case, but clearing your cache and cookies in your browser settings can help reload the page.
4. Fix your local DNS server
Your device and router also save data through its local DNS. Sometimes, these data can be outdated and corrupted, too. So, restart your device or router to refresh your local DNS server.
You can also try switching to a public DNS, such as Google DNS or Cloudflare DNS, and see if it helps.
5. Wait and retry later
If all else fails, consider waiting a few minutes and returning afterward. This might be your best solution since an HTTP error 503 often means the server is overloaded or has ongoing maintenance work.
Learn more about troubleshooting errors with Domain.com
Fixing HTTP error 503 can be frustrating, but understanding why it happens and how to fix it maintains a smooth sailing online journey. Taking the right steps can prevent future downtime and improve your online experience.
To learn more about diagnosing and fixing HTTP errors, visit Domain.com today. You’ll find in-depth guides to keep your website and browsing experience hassle-free.
