How to fix the 400 Bad Request error (iOS)

The 400 Bad Request error can appear if the URL was written incorrectly (a spelling mistake has been made). for example, if you wrote google.comm instead of google.com, you would receive an error. Add adding extra space or character can qualify as a spelling mistake, too. In this case, the solution is simple, type the correct URL.

If you enter a URL manually, before hitting the Enter button, make sure that you typed the URL correctly.

Web browsers are far more complex than they seem. They are made of processes and tools working together synchronously to enable us browse the Internet smoothly. One of those processes failing can lead to this error. Restarting the web browser can also help you fix 400 Bad Request error. As browsers tend to run long hours, and we visit a wide variety of websites during the day, maybe one of them made a plugin on your web browser unresponsive, or a process got stuck. To make the plugin responsive again, and restart stuck processes, restart the web browser.

Close the web browser, wait for a couple of minutes, and open it again.

For more solutions on how to close or quit web browsers, check out the guide on how to close apps effectively.

When we visit a website for the first time, cookies and cached data are stored on our web browsers so that the next time we open the website, it will load faster. Even though cookies and cached data are meant to facilitate your web browsing experience, corrupt cookies and cache can do quite the opposite, one of the results being this error. What you need to do, to resolve the conflict is to clear the cookies and cached data, and start from scratch. Once the corrupt ones are cleared, the next time we visit a website, clean cookies and data will be stored to our web browser.

If you have never cleared the cache and cookies so far, check out the guides below, applicable to more web browsers, installed on computers, smartphones, and tablets.

How to delete browser cookies

How to clear the browser cache

The DNS (Domain Name System) settings are part of our ID that grants us access to browse the Internet. They are assigned to us, and managed automatically by the Internet provider we connect to. On our devices, they could be set to be managed automatically, or manually. If settings are managed manually, the margin for errors is greater than if the settings were managed automatically, as we will need to supervise if the settings are still valid.

If the error was caused by DNS settings, in order to fix it, you need to flush the DNS. Flushing the DNS is like clearing browser cookies and cached data, or unclogging a clogged pipe, but on a deeper level. Once cleaned, it many issues with Internet access, known and unknown, including the Bad Request - Invalid URL error will be resolved.

Note: If you have never flushed the DNS before, the how to flush the DNS guide can help you. Feel free to check it out.

The router is the main Internet distributor in our household. From the wire it spreads it throughout the ether so that all our devices can connect to it via Wi-Fi. Maybe something went wrong with the router, and it cannot share Internet properly, resulting in the HTTP Error 400. It may have got stuck in a loop, after a minor Internet downtime, failing to reconnect to the Internet.

If the router is the cause of this error, you need to restart it, in order to fix the error. You can restart it effectively by power-cycling it (unplugging it from the power strip and plugging it back in after 5 minutes).

Note: If you use a modem, make sure to restart it, too, because it may be the culprit as well (it shares Internet to the router, or it has a Wi-Fi module you connect to).

Restarting your smartphone or tablet is an easy way to address numerous problems, including Bad Request: Error 400. You will restart all the background processes and tasks that are running on your device in the background, some of which are part of the operating system, with their purpose being to make sure you can use your device seamlessly.

Restart it by pressing and holding the power button, and selecting the turn-off option. Wait for 5 minutes before turning your device back on.

Maybe the Internet service provider/carrier is the reason for this error. Sometimes, although extremely rare, some websites are inaccessible because they were blocked by the ISP, for a reason, or it's possible that there are service interruptions your ISP needs to address.

Contact the support team of your Internet Service provider, let them know you have issues accessing website, share the URL address(es) of the website(s) you can't visit, and they will guide you what to do. If the issue was caused by them, they will address it.

DNS settings are a must if we wish to browse the Internet. Along with the IP address, they are part of our online ID. There are two ways to obtain these settings, automatic, and manual. If DNS settings are set to be obtained automatically, they are managed by the Internet provider you are currently connected to. If the DNS settings are obtained manually, then you as a user is in control of them. It's possible that your current settings became unresponsive, which is most likely the case if you obtain them manually, or there is a temporary issue with them, causing this error message.

In order to fix this error, you can update the current DNS settings. You can set to obtain them automatically, or manually.

If it's the ISP DNS settings that are the culprit, and you decide to obtain DNS settings manually, feel free to use Google's DNS settings:

For IPv4, use 8.8.8.8 and 8.8.4.4.
For IPv6, use 2001:4860:4860::8888 and 2001:4860:4860::8844.

If you are not sure how to change the DNS settings, check out the how to change the DNS settings guide.

With proxy settings in place you access the Internet as a different person, from another location. They can be compared to plane tickets. You can't board a plane unless you have valid tickets. It is possible that the proxy settings are the reason behind this error. To know this for sure, you can try disabling them first. If you use proxy using a software, disable it.

If the proxy settings were indeed the culprit, to fix this error, you need to use valid proxy settings. Access your device's proxy interface and enter valid proxy settings that are proven to work. Then, restart your device and check if you can recreate this error.