What Is a 504 Error? 

Key takeaways: 

• 504 errors happen when servers don’t respond on time. This is usually caused by server overload, DNS issues, firewall blocks, or slow upstream servers. 

• These errors hurt both SEO and user experience. They can lead to high bounce rates, lost traffic, and lower search rankings if not resolved quickly. 

• You can fix and prevent 504 errors through clear, actionable steps. Site owners and developers have several options, from checking plugins and server logs to implementing load balancing and regular maintenance. 

You’ve surfed the internet countless times and are probably familiar with a 504 Gateway Timeout error message. Like when you visit a web page expecting to see the content that you’re looking for, but you get a gateway timeout error message instead. Such a hassle, right? 

As a website owner, you have to avoid this because it affects your business reputation and it impacts your SEO, which could eventually affect your revenue. 

Now let’s get deeper into this gateway message, how it adversely affects your website, and how to fix it.  

Introduction to HTTP server errors 

When a website doesn’t load correctly, your browser often shows an HTTP status code to explain what went wrong. These codes are grouped by type like 404 for “not found” or 500-level errors for server issues. 

504 errors fall into that 500-level group. These errors mean something went wrong on the server’s side, not the user. But not all 500 errors are the same. For example: 

• 502 Bad Gateway happens when a server receives an invalid response from another server. 

• 504 Gateway Timeout means that the server acting as a gateway did not receive a timely response from an upstream server it was waiting on. 

Both errors usually involve communication problems between servers, but 504 is more about delays, while 502 is about broken responses. Knowing the difference helps you fix the issue faster and avoid unnecessary guesswork. 

What is a 504 gateway timeout? 

A 504 Gateway Timeout is an HTTP status code indicating that there is a communication issue or problem between servers. This is when a web server didn’t receive a quick or timely response from another server (upstream server) to accomplish a request. In simpler terms, you get this error when the two servers are not communicating in a timely manner. 

Variations of HTTP 504 gateway timeout errors 

There are different variations of the 504 Gateway Timeout error as websites are allowed to customize this. Here are the common variations of this error message: 

• 504 Gateway Timeout  

• 504 Gateway Timeout NGINX 

• Gateway Timeout Error 

• Error 504 

• HTTP 504 

• HTTP Error 504 Gateway Timeout 

• 504 Error 

• The page request got canceled because it took too long to complete 

• This page isn’t working – Domain took too long to respond 

• 504 Gateway Time-out – The server didn’t respond in time 

What causes a 504 gateway timeout?  

A 504 Gateway Timeout usually happens when one server is waiting for another server to respond, but it takes too long. There are a bunch of reasons this can happen, from traffic overload to security settings getting in the way.  

Here’s a quick rundown of what might be causing it: 

• Spam or Distributed Denial of Service (DDoS) attacks 

• Website Content Delivery Network (CDN) delays 

• Firewall blocking requests   

• Website hosting issues 

Spam or Distributed Denial of Service (DDoS) attacks  

A 504 Gateway Timeout could mean your site’s being hit by bots flooding it with too many requests. These attacks can overwhelm your server by crawling your site at an excessive rate, using a lot of resources. If it’s a DDoS attack, the abnormal traffic can make your site throw a 504 error.  

Check your access logs to spot any IP addresses that are making a ton of requests. You can block those IPs from accessing your site once you’ve identified them.  

Website Content Delivery Network (CDN)  

A Content Delivery Network (CDN) is a network of servers that delivers website content from locations closer to the user, improving speed and reliability. 

Sometimes a CDN service can’t get a quick response from your web server, which could cause a 504 error. To fix this, you might need to bypass or temporarily disable the CDN. Just remember that turning off these services might require DNS changes, which can take some time to take effect.  

To check if the issue is with your hosting server or the CDN, you can bypass the CDN by editing your computer hosts file and pointing your domain directly to the hosting server. After making the change, clear your browser’s cache and reload the site. If it works fine, the problem is likely with the CDN.  

In that case, log in to your CDN control panel and temporarily disable the service to resolve the issue.  

Firewall blocking requests  

Firewalls keep out all the unwanted traffic such as spam and bots. But sometimes, firewalls can mistakenly block legitimate requests, especially if they think the request is a security threat. Whenever this happens, the server can’t respond to the request, and you get a 504 timeout.  

So, if you control the server, check your firewall rules to make sure they’re not blocking valid traffic. Maybe your firewalls are set too strict, or there’s a misconfiguration causing them to block legitimate requests.   

Website hosting issues  

The server that hosts the website may be having problems. This could be anything from a simple misconfiguration to something more serious like hardware failure. When the server isn’t responding in time, the request times out and you get a 504 error.  

You could talk with your hosting provider to see if there’s an issue at their end. If you’re managing your own server, check the server’s health and logs for errors. It could be a server crash, or a problem with the software it’s running.  

7 ways to fix 504 gateway timeout  

What are some common ways of fixing a 504 error? Here are some remedies for you: 

• Refresh the web page 

• Double-check your proxy server settings 

• Look for DNS issues 

• Restart network devices 

• Check your WordPress plugins, themes, and database 

• Locate and fix faulty firewall configurations 

• Contact your hosting provider 

Refresh the web page 

Sometimes, a 504 Gateway Timeout error will show when there’s too much website traffic. In such cases, simply refreshing the web page can resolve the problem. 

Aside from website traffic, overloaded web servers are also the reason for this error. What you can do is access the site by using a different browser. You can try this method after reloading or refreshing your web page. 

Double-check your proxy server settings 

Proxy servers serve as a gateway between a device and the internet. It’s used to enhance the user’s privacy, enhance performance for users by caching frequently accessed web pages, restricting access to certain websites, and accessing content that’s specific to a certain region only.  

Incorrect proxy settings can also cause connectivity issues that result in the 504 error message. Check to see if your proxy server settings are correct, then revise it or disable it. Reload the page once you’re done. 

Look for DNS issues 

Another potential cause of a 504 Gateway Timeout error is DNS issues. This can happen when you’ve recently changed hosting providers or servers. What you can do is wait for the  DNS records to propagate completely.  

You may need to wait for DNS records to fully propagate or try flushing your local DNS cache to clear out old records and force your device to fetch fresh ones. You can use a DNS checker to see if your domain name has propagated globally already.  

Restart network devices 

Restarting your network devices helps refresh the connection between the web server and the upstream server. To improve your network or internet connection and resolve the error message, follow these steps: 

1. You should have a router from your internet service provider. Unplug the power cord from the outlet. 

2. Wait a couple seconds. 

3. Plug the power cord in again. 

4. Wait for the network device to finish turning on.   

Once you’ve completed all the steps above, check the website to see if it’s already working.  

Check your WordPress plugins, themes and database 

Broken or faulty plugins and themes can cause a 504 error. To check if a plugin is the issue, temporarily disable your plugins in the WordPress admin dashboard. Refresh the page and check if it worked. If the error goes away, you can re-enable each plugin one at a time until you find the plugin that is causing the issue. 

Similarly, a corrupted WordPress database can also cause a 504 error. Some of its causes include a server interruption, a hardware failure on the server where you host your WordPress website, and a crashed server. What you can do is use a WordPress plugin for the database repair or use phpMyAdmin to remedy this. 

Locate and fix faulty firewall configurations 

Firewalls protect your network from unauthorized access or malicious attacks, but they can also block or delay the response from the upstream server, which causes the 504 error. If you encounter this error, you can try deactivating your firewall temporarily to access the website you’re trying to reach. 

Contact your hosting provider 

If you’re having trouble resolving the 504 error yourself, you can contact your hosting provider for assistance. Your web host should provide a support team who can help you diagnose the root cause of the error and provide you with a solution. 

How to prevent 504 gateway timeout errors  

No one wants to deal with 504 errors over and over. A bit of planning and regular maintenance can go a long way to keep them from happening in the first place. Here’s what you can do to stay ahead: 

• Optimize your server 

• Implement load balancing 

• Monitor and maintain backend services 

• Perform regular maintenance and updates 

Optimize your server  

Slow or overloaded servers are one of the most common causes of 504 errors. Ensure your server is properly set up to handle traffic. This could mean upgrading your hosting plans if your site is getting more visitors than usual. Updating your software to their latest versions also helps avoid bugs that can slow things down.  

Implement load balancing  

A load balancer can distribute traffic evenly across multiple servers. Even during traffic surges, it guarantees that your website remains responsive. This helps prevent timeouts and keeps the user experience smooth by balancing traffic across servers. 

Monitor and maintain backend services  

Many 504 errors stem from backend services like databases or external APIs.  You can optimize database queries and check for any potential issues with third-party services that your site depends on. Catch problems before they lead to a timeout error by staying on top of these systems.  

Regular maintenance and updates  

Routine maintenance is key to preventing server issues. It includes performing regular software updates, patching security vulnerabilities, and checking server logs for errors.  You can catch issues early and avoid unexpected downtime by proactively maintaining your infrastructure that leads to 504 errors.  

How 504 errors impact SEO and user experience 

A 504 Gateway Timeout affects both search engines and real users. Whether it’s Google’s crawlers or your next customer, prolonged timeouts signal that your website is unreliable. Here’s how that impacts your site overall: 

Search engine crawling and SEO risks 

• Downtime leads to missed indexing. If crawlers encounter repeated 504 errors, your pages might not get indexed properly or at all. 

• Ranking drops. Google interprets prolonged unavailability (especially beyond 6 hours) as a sign of a poor user experience, which can hurt your rankings. 

• Potential deindexing. If entire sections of your site remain inaccessible, they may be removed from search results. 

User experience and trust 

• Frustrated visitors. When users can’t load a page quickly, they often leave without acting. 

• Higher bounce rate. A 504 error page can increase bounce rates and reduce engagement, especially on high-intent pages like product listings or checkout. 

• Lost revenue. For eCommerce or lead-gen sites, these errors can directly affect your bottom line. 

If you want to go further, here’s some simple tips for your user experience. 

• Use temporary redirects or a custom 504 page to soften the SEO hit while resolving the issue.  

• Customize your 504 error page to explain what’s happening, offer alternative links, and maintain trust. 

Fixing 504 errors quickly and communicating clearly with both bots and users can make all the difference. 

Advanced troubleshooting for developers 

Even after going through the standard fixes, 504 Gateway Timeout errors can persist, especially on larger, more complex websites. Here are advanced-level steps developers can take to dig deeper and resolve the issue from the server side. 

Review and increase proxy timeout settings 

Web servers like Nginx or Apache may have default timeout limits that are too low for longer server responses. You can increase these timeout values in your configuration files: 

For Nginx: 
In your nginx.conf, look for or add: 

proxy_connect_timeout 600;  
proxy_send_timeout 600;  
proxy_read_timeout 600; 
send_timeout 600; 

For Apache: 
Modify or add: 

ProxyTimeout 600 

After making changes, reload or restart your server. 

Analyze server logs 

Check server logs (like access.log, error.log, or application-specific logs) to identify failed upstream requests, timeouts, or recurring error patterns. These logs often pinpoint exactly which part of your stack is lagging or failing. 

Test upstream server response time 

Use tools like cURL to test the response of any external or upstream servers your site relies on.  

Example: 

curl -I https://your-api-endpoint.com 

If these servers are slow or unresponsive, they may be the cause of the timeout. 

Use traceroute and ping for network diagnostics 

To check for network routing delays or packet loss between servers, run: 

traceroute {yourdomain.com} 

ping {yourdomain.com}

This helps identify if there are DNS or ISP-level issues between your server and a third-party service. 

Adjust buffer and header limits 

Large HTTP headers or responses can exceed default buffer settings. In Nginx, increase values such as: 

proxy_buffers 16 32k;  
proxy_buffer_size 64k; 

This prevents 504 errors caused by overloaded buffers when handling large requests or headers. 

Stop 504 errors in their tracks 

504 Gateway Timeout errors can frustrate visitors, hurt your SEO, and cost you valuable revenue. Staying on top of server performance, applying fixes, and performing regular maintenance will keep your website fast, reliable, and trusted. 

Don’t let 504 errors derail your business. Take charge of monitoring your site and partner with Network Solutions for secure web hosting and great website security to keep everything running smoothly. 

Frequently asked questions