How to Fix Cloudflare Error 500: Internal Server Error

The Cloudflare error 500: Internal Server Error is an indication that there’s something wrong with your origin server. Unlike error 523: Origin is Unreachable, your server can receive and respond to Cloudflare’s requests but throws an error in response. With Error 523, your server doesn’t respond, so Cloudflare doesn’t know whether your server even exists.

The 500 “Internal server error” can also be a problem at Cloudflare’s end – as the screenshot shows in the featured image. This is rare, but if it happens, here are ways to address the issue.

1. Database Errors on your Site are the Most Common Cause

Cloudflare throws the “Error 500: Internal server error” most commonly when your server responds to a request with a database failure. I’m sure many of you are familiar with the following screen if you’ve been a WordPress user for a long time:

Unfortunately, it’s impossible to provide a single reason for this. NameHero has a helpful article on how to fix the error in establishing a database connection error. As you can see from that article, the problem can range from an invalid username and password to a problem with the NameHero servers. It can even be because one of your plugins misbehaved. Bottom line – this is something you will have to test by yourself.

2. Troubleshoot the Problem by Pausing Cloudflare

To debug the problem, you should pause Cloudflare – at least temporarily. This will reduce the number of working parts and allow you to focus on your server. You can access this option from the Cloudflare dashboard overview, as shown here:

Another reason to pause Cloudflare is so that you can see your actual error page instead of the one generated by your site since this might give you more information about what went wrong.

3. When to Contact Cloudflare for Error 500

While it’s true that most of the time, your website is the origin of this error, it could be a problem with Cloudflare itself. One way to check is to see if the error picture has a red cross (X) over the middle Cloudflare icon like this:

Your host isn’t the problem in the above example – Cloudflare is! Another way to check is to see if the words “cloudflare” or “cloudflare-nginx” appear in the error message. If they do, then you need to reach out to Cloudflare support with the following information:

1. Your domain name
2. Your timezone and when the error occurred
3. The output of the following URL: https://www.yourwebsite.com/cdn-cgi/trace

The last step requires some explanation. You can use the following URL (replace “yourwebsite” with your actual domain name) to send troubleshooting information to Cloudflare about any request to your server:

https://www.yourdomainname.com/cdn-cgi/trace

Here’s a sample output from my website with the domain name wp-tweaks.com:

This isn’t sensitive information since it’s a publicly accessible URL. Anyone can view this information by using your domain name and appending “/cdn-cgi/trace” to the end. But it’ll help Cloudflare diagnose what’s wrong with your site in case they’re the reason for the 500: Internal Server Error.

It Helps to Have a Pro Account for Cloudflare Support

It’s much harder for Cloudflare users on the free tier to get support since the documentation specifies that they can only contact Cloudflare for account, billing, and registrar issues. But if you click the “Support” dropdown box in the upper-right corner, you can create a support ticket for 500 errors, as shown here:

I’m not sure how this ties into Cloudflare’s claim that free accounts can’t create tickets, but clearly they can.

Tips for Preventing Error 500: Internal Server Error on Cloudflare

Because the causes for Cloudflare’s error 500 are so varied, I can’t give you any specific tips for preventing it. But here are a few things that might be helpful to prevent it from occurring, as well as how to head them off as quickly as possible.

Ensure that your Server Has Sufficient Resources

Since an overworked database is a significant cause of this error, one way to reduce your chances of facing it is to ensure that your server has the resources it needs over and above what’s strictly required to account for spikes in demand. This means maintaining a web hosting plan that’s suitable to your traffic and kind of website.

Some sites are primarily static HTML (like mine) and don’t require a lot of database interactions – especially when you’ve set up caching properly. Others display real-time data, present most of their content within a member area and are more database-intensive. The latter category requires either higher shared hosting plans or even a VPS server. Some hosting providers provide a “burst” capacity, but this requires a specialized architecture and won’t work on ordinary VPS systems.

Maximize your Database Capacity

Beyond improving your server’s overall capacity, you should look at increasing your database server’s capacity. For example, if you’re inserting large amounts of data into the database using a PHP script, you could look into tweaking variables controlling the maximum execution time of a query.

You can also try increasing the number of maximum simultaneous connections to the database if you feel this might be the bottleneck. Depending on your web hosting plan, you may or may not have direct control over these variables. Most people don’t need to modify these settings, so that you might be the exception.

But the general theme is to increase capacity – whether the server itself or the database.

Set up Cloudflare Health Checks

You might not be able to prevent all Cloudflare 500 errors, but you can aim to respond to them as quickly as possible. To do this, you can create health checks in Cloudflare. Unfortunately, users on the free Cloudflare tier don’t get access to health checks, whereas if you’re on the Pro plan, you get 10. Here’s an example of a Cloudflare health check for my website:

You can also create notifications for when the status of your site changes from “Healthy” to “Unhealthy” and vice-versa. Timely notifications will give you a heads-up if your server responds with a 500: Internal server error, and you can fix it before your customers notice.

Of course, Cloudflare isn’t the only game regarding health checks. If you don’t have a free plan, I suggest you try StatusCake, which I’d reviewed earlier while considering alternatives to the Jetpack WordPress plugin.

Cloudflare’s “Always Online” Will Give you Some Breathing Space

While it’s not to be relied upon, enabling the “Always Online” functionality of Cloudflare can keep your site up in a limited manner while you fix the underlying problem. Thanks to its integration with the Internet Archive, Cloudflare can serve most of your publicly facing pages even when the underlying server generates an error. It’s a temporary solution, but every bit helps in an emergency!

Bottom Line: Error 500 is Generic and Indicates a Server Issue

The takeaway is that Cloudflare’s Error 500 means there’s something wrong with your server – either a PHP misconfiguration or a database issue. There’s no single reason why this occurs, so the onus is on you to debug your server and figure out what’s wrong. Use health checks to stay on top of potential server malfunctions, and good luck!