400 Bad Request Error: What is it and how to fix it with Apache Proxy & SSL
Written By
Ananaya Kandpal
Reading time: 4 minutes
Are you getting tired of the 400 Bad Request message when you try to access a website? And you have tried all the possible things you can do, like reloading the page, using a different browser or device, but nothing seems to work.
Well, the 400 Bad Request error refers to a common HTTP status code that represents that the server could not understand the request due to invalid syntax. This error can be generally frustrating when it occurs in environments that use an Apache reverse proxy and SSL.
Knowing the root causes and implementing the right solutions is crucial for maintaining a better user experience. This post will walk you through the main causes of this error in an Apache reverse proxy setup and offer comprehensive solutions to solve it.
What is a 400 Bad Request Error?
A 400 Bad Request error is basically a part of the HTTP 4XX status codes, which shows the server can't fulfil requests because of a client-side error. It mainly exists when your request is corrupted, invalid, or too big. As a result, the server can't process the request and shows a 400 response code. So, what are the main root causes of this error? Here are the possible reasons:
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Wrong syntax in the URL: The web address has typos or invalid characters. Even a small error, like having extra space or deleting special characters like =, could cause the 400 error.
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Issues with Your Browser: Corrupted cache files, outdated cookies, and conflicting browser extensions prevent the server from processing your request accurately.
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Outdated DNS Cache: Your cached data becomes invalid when the website you are attempting to access modifies its DNS records. The server won't be able to obtain the right IP address as a result.
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The File Size is too Large: Your HTTP request consists of cached images, browser cookies, or uploaded files that exceed the server's limits.
Key Steps to Fix a 400 Bad Request Error
The 400 response code is a client-side error, which means something is wrong with your request instead of the site's server. To fix this error, you need to ensure everything is working properly on your end.
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Check your Internet Connection: When you try to access a website, your browser sends a request to the server, which then sends back a response. A slow internet connection can cause the data to be transmitted incompletely, resulting in the 400 status code. So, before applying other troubleshooting methods, it will be nice to check your internet speed.
For web browsing, a good ping rate should be between 51 to 150 milliseconds. Anything beyond that means your internet speed is slow. In this case, you need to try using another network and see if the 400 error is solved or not. If your connection works just fine, but the error remains the same, move on to the second step.
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Fix Typos and Invalid Characters in the URL: Each time you enter a URL in the address bar, make sure there are no spelling mistakes or wrong usage of special characters. For example, if you type www.net2secure.com/% in your browser, you will get this error:
Why? Because this particular web address doesn’t exist.
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Clear Your Browser’s Cache & Cookies: A cache is a temporary storage location used to keep copies of all web pages you have visited so far. So, the next time you want to access the same page, the browser can serve that content faster than before. Meanwhile, cookies save your crucial information like browsing history, login details, and preferred settings. It enables browsers to offer a seamless and personalized experience.
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Deactivate Browser Extensions: A few browser extensions interact directly with cookies. Think about password managers that keep your login credentials, or ad blockers that keep a list of blocked domains and known ad scripts. When your cookies are leaked, your extensions will send the incorrect information to the server. The server rejects your requests as it can’t find the lost data. Several browser add-ons may also modify HTTP headers, block JavaScript with other extensions, all of which can trigger a 400 error.
Thus, a 400 Bad Request error happens when something is wrong with your request. It’s either because you enter an invalid URL, your cache files and cookies are outdated, or you upload a file that increases the server's limits.
