11 Common API Errors That Can Ruin Your Day and How to Troubleshoot Them

Do you ever feel like a computer system has been putting up brick walls every time you try to make progress? If you’ve been working with APIs recently, it sounds like you could be dealing with a few common errors.

Those error messages can have anyone scratching their head, but fear not! We’re here to help break down some of the more common errors and how best to address them, so your day doesn't become one giant headache.

This blog post will list 11 API errors that often pop up and how to troubleshoot them. Let's get started!

HTTP Status Code Overview

Before we dive into the specific errors, here’s a quick overview of HTTP Status Codes. HTTP status codes are the main indicator of API errors. They are the server’s way of letting you know what it thinks about your request.

If the status code is between 200 and 299 (inclusive), this indicates that the API call was successful. But if there’s an error, you’ll get a 4xx or 5xx status code.

4xx Status Codes – Client Error: The client (you, the API user) has sent a request that the server could not process correctly.

5xx Status Codes – Server Error: The server encountered an unexpected condition that prevented it from fulfilling the request.

These errors can be resolved in many cases by following the troubleshooting tips provided.

11 Common API Errors and Troubleshooting Them

Now that we’ve got the basics down, let’s look at some of the more common API errors.

Common API Errors

1. 400 Bad Request Error
2. 401 Unauthorized Error
3. 403 Forbidden Error
4. 404 Not Found Error
5. 408 Request Timeout Error
6. 500 Internal Server Error
7. 502 Bad Gateway Error
8. 504 Gateway Timeout Error
9. 505 HTTP Version Not Supported Error
10. 507 Insufficient Storage Error
11. 508 Loop Detected Error

1. 400 Bad Request Error

This error is one of the most commonly encountered API errors, and it occurs when a server can’t parse the request itself. This could be caused by an incorrect URL, something wrong with how the API request was composed, or even an issue within the application itself.

To troubleshoot this issue, start by examining the URL and ensuring it looks correct. Then, check your API request's syntax to ensure everything is formatted correctly. If this doesn't solve the issue, you should go back into the application and search for any obvious errors.

2. 401 Unauthorized Error

This API error occurs when a server cannot authorize the user’s credentials. This could be caused by an incorrect username or password or even a lack of permission access.

To troubleshoot this API error, start by confirming that your username and password are correct. If they are correct and you’re still receiving the error, then it could be a permissions issue; if so, contact your API provider for further assistance.

3. 403 Forbidden Error

This API error occurs when a server refuses to fulfill a request from the client due to authorization issues or other restrictions put in place by the API provider.

To troubleshoot this API error, ensure you have adequate permissions for making requests on the API endpoints in question. Then, check the API documentation to make sure that you’re sending valid data parameters with your requests. Finally, verify that no external restrictions are in place that may be blocking access to the API endpoints in question.

4. 404 Not Found Error

This API error occurs when a server can’t locate the requested resource from the API provider. This could be caused by an incorrect URL or something wrong with how the API request was composed.

To troubleshoot this API error, start by verifying that the URL is correct. It’s also important to check the API documentation to make sure that you’re using the correct data parameters with your requests. Finally, contact your API provider for further assistance if all else fails.

5. 408 Request Timeout Error

This API error occurs when a server doesn’t receive a response from the client within a specified amount of time and that the connection has been terminated.

To troubleshoot this API error, double-check that the URI is correct, check your internet connection, reload the page, or check your web server's timeout settings.

6. 500 Internal Server Error

This API error occurs when a server encounters an unexpected condition that prevents it from fulfilling the API request. This could be caused by an issue with the API provider’s internal systems or there could be something wrong with how the API request was composed.

To troubleshoot this API error, check the API documentation to ensure that you send valid data parameters with your requests. Then, contact your API provider for further assistance in resolving any underlying issues within their internal systems.

7. 502 Bad Gateway Error

This API error occurs when a server acts as a proxy and receives an invalid response from another upstream server. This could be caused by the domain name not resolving to the correct IP, the server is not reachable, or the firewire blocking the communication.

To troubleshoot this API error, check your domain name, verify that your server is reachable, or check your firewall logs.

8. 504 Gateway Timeout Error

This API error occurs when a server acts as a proxy and doesn’t receive a response from another server upstream within a specified time. This could be caused by an issue with internet connectivity or something wrong with how the API request was composed.

To troubleshoot this API error, first, verify that your internet connection is functioning properly and then check the API documentation to make sure that you’re sending valid data parameters with your requests.

9. 505 HTTP Version Not Supported Error

This API error occurs when a server doesn’t support the client's requested version of the HTTP protocol.

To troubleshoot this API error, verify that you are using a supported version of the HTTP protocol (usually 1.1). Then, contact your API provider for further assistance in resolving any underlying issues within their internal systems.

10. 507 Insufficient Storage Error

This API error occurs when there isn’t enough storage space available on a server to fulfill an API request.

To troubleshoot this API error, you could raise the standard hosting package you have or try optimizing the repositories if there's excess page traffic.

11. 508 Loop Detected Error

This API error occurs when a server identifies an infinite loop (a cycle of API requests). This could be caused by too many redirects in a chain that prevents the requested resources or URL from rendering.

To troubleshoot this API error, try to identify which API calls are causing the loop, then contact your API provider for additional assistance in resolving any underlying issues.

Wrapping Up API Common Errors

API errors can be caused by multiple factors ranging from server-level issues to incorrect API requests. It’s important to understand the most common API errors and how they can be identified for troubleshooting.

Additionally, it’s always a good idea to make sure that your internet connection is functioning properly before attempting to troubleshoot API errors, as this could influence the outcome of some API requests. Lastly, it’s also important to regularly monitor the performance of your APIs to detect API errors early and mitigate their impact on your users.

When API errors are handled properly, they can be resolved quickly with minimal disruption to your API clients. With this guide, you should better understand the most common API errors and how they can be identified and troubleshot.