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FIX: HTTP error 400 on Windows 10/11 computers
7 min. read
Updated onOctober 4, 2023
updated onOctober 4, 2023
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Key notes
Also known asBad Request error, the400 erroris an HTTP response status code that just means you made an incorrect request, or it was corrupted and the server was unable to find the requested URL.
The error is usually caused when you enter the wrong URL in the address bar, which is known as invalid syntax. This can be frustrating and a challenge when it comes to fixing the problem, as the codes represent complex relationships between the client and web app, web server, and multiple third-party web services.
Usually, status codes in the 4xx category are client-based error responses, and when you get one, it doesn’t necessarily mean it’s a client-related issue i.e. yourweb browseror device you’re using to access the web.
However, because the400 Bad Request errorusually stems from theclient-side, the issue has to be resolved from therein.
Before trying the solutions below, make a thorough backup especially if you were making modifications to your site or app so that you have a clean ground from which to test if the solutions below helped resolve the 400 Bad Request error.
How do I fix theError 400 URL was not founderror?
1. Switch browsers
Sometimes, the quickest way to fix some errors is by switching browsers. It will not guarantee a fix for HTTP error 400, but it’s still a smart choice.
Our recommendation is theOpera One browser. A top choice that offers more benefits than Chrome, Firefox, or others.
For example, you get crypto mining protection, which is not available in Chrome. If the website you want to visit has been highjacked with a hidden crypto-miner, it might prevent you from being able to run the page. Opera One stops that hidden process.
You also get a good ad-blocker and an unlimited VPN. The VPN is also free. It might be useful if the page is geo-restricted. For your personal IP, it might return an HTTP error 400, while for other users in a different country it might show the content.
Of course, you can easily import your bookmarks from the current browser and make the switch permanently. You will also get access to some interesting features like sidebar integration with Facebook Messenger or WhatsApp, Workspaces, Tab Islands and AI.
Opera One
2. Clear cookies
An invalid or duplicate local cookie can cause 400 Bad Request Error to display when it is conflicting with another session token for a different user, so one of you gets the error. In this case, check for cookies relevant to the site or app that is bringing up the issue.
We will show you how to clear cache and cookies if you’re using Google Chrome,Microsoft Edge(IE), or Firefox browsers. If you don’t want to follow this tedious process, you can also choose to clear the cookies, cache, and more with one click using third-party software.
Google Chrome
Microsoft Edge
Firefox
You can delete cookies for one website or delete all cookies altogether. For one website, do this:
To remove all cookies, do this:
So these are the complete steps for the most common browsers.
Alternatively, you have the option of using practical tools that can wipe out browser cookies completely, freeing up your memory in a few moments.
If you need to erase potential harmful cookies from your browser easily, this tool helps you to refresh your system by getting rid of unnecessary files.
Plus, delete your browsing history regardless of what browser you’re using. Such a method can as well help you repair registry issues that may cause system errors.
Therefore, you should consider using the mostefficient cookie cleaner softwareyou can find right now.
3. Check your URL
The 400 Bad Request error usually happens when you type a wrong or incorrect URL, so the first step would be to check if the URL is correct. Check for spellings, cases, path, query, or fragment portions after the domain name, and ensure they’re correct. Also, check for improper special characters.
4. Upload smaller files
The 400 Bad Requesterrorcould also be caused when you try toupload large files. Try and upload a smaller file and see if it helps.
This includes uploads that aren’t from your computer or files sent to other computers that are deemed uploads from the server in your web app.
5. Sign out and sign in again
If the web app has user authentication, try signing out and then signing in again. If you cleared cookies, you should be automatically logged out when you try loading the page again.
The 400 Bad Requesterrorcould be coming up due to a string from the previous session sent from the server to the client to identify it for future requests.
6. Check common software packages on the server
You could be running some software or content management systems that once modified could result in 400 baderrorrequests. To resolve this, do the following:
7. Troubleshoot your server
8. Reset your browser (Chrome)
The new settings will also apply across all devices you’re signed into.
Let us know if the solutions above helped resolve 400 – that’s an error – the requested URL was not found on this server, by leaving a comment below.
Milan Stanojevic
Windows Toubleshooting Expert
Milan has been enthusiastic about technology ever since his childhood days, and this led him to take interest in all PC-related technologies. He’s a PC enthusiast and he spends most of his time learning about computers and technology.
Before joining WindowsReport, he worked as a front-end web developer. Now, he’s one of the Troubleshooting experts in our worldwide team, specializing in Windows errors & software issues.
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Milan Stanojevic
Windows Toubleshooting Expert
Before joining WindowsReport, he worked as a front-end web developer. Now, he’s specialized in Windows errors & software issues.
