How to fix ERR_HTTP2_PROTOCOL_ERROR in Google Chrome

What is ERR_HTTP2_PROTOCOL_ERROR

ERR_HTTP2_PROTOCOL_ERROR is quite a popular error that may occur in any browser including Chrome, Edge, Opera, Firefox, and so forth – mostly on Windows 10/11 systems. HTTP2 is a new protocol that replaced its HTTP precursor with a faster time response by consolidating files into one packet and transmitting them to the server. One of the reasons why ERR_HTTP2_PROTOCOL_ERROR occurs is because the website you are trying to visit does not support the HTTP/2 protocol – often due to cheap hosting or that the administrator of the website has not enabled this protocol on the server. This reason would be relevant if you are unable to visit one specific webpage. Otherwise, if that is the entire browsing you are facing problems with, then it could be related to more general causes like outdated browser versions, incorrect date & time settings, conflicting browser add-ons, overstuffed cache, or even experimental features leading to connection conflicts. Below, we have compiled a guide with solutions that will potentially resolve the problem and get your browser back to working again. Note that the instructions below are mainly focused on resolving the problem in Google Chrome, however, you can also use them for performing similar actions in other browsers too.

1. Make sure your browser is up-to-date

If your browser is still working on an older version, it can be the reason why new HTTP2 protocols end up rejected. Thus, make sure you have the latest browser version installed by doing the following:

1. Left-click on three-dot menu in the top right corner.
2. Choose Settings and navigate to About Chrome on the left pane.
3. Chrome will automatically search up new updates and tell you if it is up-to-date already.
4. If a new update will be installed, you will have to click Relaunch to reboot the browser as well.

After this, check whether problematic pages became usable again.

2. Set date & time to update automatically

If you have an incorrect date and time set on the system, it may cause the error to occur, as data packets may be rejected by the server due to an incorrect time stamp. We recommend you check it using the following steps:

1. Press Windows key + I buttons and navigate to Time & language.
2. Then go to Date & time and enable the Set time automatically option.

3. Disable third-party antivirus

If there is a third-party antivirus installed on your PC, try to disable it and check whether you can visit problematic pages again. Antimalware firewalls can sometimes create conflicts with connections to certain or many websites. If after disabling your antivirus, everything began working fine without connection problems, then your antivirus was the reason for that. If you continue getting the error after launching your antivirus back, you may consider trying another less conflicting software. Our advice is MalwareBytes – a trusted and talented team of experts constantly maintaining their software to combat both minor and global threats. It is now available for Windows 11 as well. You can download it now using the link below and try a 14-day trial of the ultimate antimalware experience for free.

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4. Disable Chrome Extensions

Some installed extensions that work in your browser may be the reason for being unable to access certain browser pages. If this is an unpopular and badly-developed browser add-on, it may conflict with opening some browser pages. We, therefore, advise you to get it/them disabled and check if it helps. In case nothing changes, feel free to turn them back on.

1. Open Chrome and click on the three-dot icon in the top right corner.
2. Hover your mouse over More tools and select Extensions.
3. Disable all the third-party extensions by clicking on the blue toggle.

After performing these steps, open the same domain you experienced problems with and give yourself feedback if something has changed.

5. Clear browser data

Another quick solution that could effectively deal with some errors is to declutter your browser from overloaded files like cache. Some browser elements memorized by Chrome and other browsers after some time of usage may create incompatibility problems while opening certain pages. Clearing up your browser data may not only resolve the issue, but also increase browser performance and free up some space. Note that clearing browser data may log you off from websites you visited before. Thus, make sure you remember your login credentials afterward.

1. Click on the three-dot icon in the top right corner, as we did above.
2. Got to More tools and choose Clear browsing data….
3. At the top, choose a time range. To delete everything, select All time.
4. Check the boxes next to Cookies and other site data and Cached images and files.
5. Then click on Clear data.

Restart your browser and try to open the website again.

6. Update drivers

Quite often, outdated network drivers can become a reason for preventing the proper connection. It can be obsolete or corrupted drivers that are no longer supported or broken. This is why it is advised to scan your Network and Wireless adapters for drivers and install them if necessary. You can do it manually or use a special utility for a faster solution. Both options are discussed below:

1. Left-click on the Start Menu button and choose Device Manager.
2. Ideally, you should update all network devices available. If there is something marked with a yellow triangle, this means you should update in the first order.
3. To do it, right-click on the driver, choose Update, and follow the on-screen instructions.
4. Let Windows search for new drivers and download them eventually.

Drivers are key to the proper configuration of your system. They are the ones providing a stable connection between hardware and your operating system. Updating a number of drivers manually may take a lot of time, rehearsing the same steps. Here you can download the best driver update utility, which will speed up the process and deal with this task on its own – Driver Booster from IObit:

Download Driver Booster

7. Disable QUIC protocol

A conflict may occur with HTTP2 and lead to the ERR_HTTP2_PROTOCOL_ERROR issue if the server hosting the website is not properly configured to handle traffic from QUIC, which is a transport layer experimental network. Below, we are going to turn it off in case it is enabled.

1. Open your browser and copy-paste this chrome://flags/#enable-quic into the search line.
2. Then set Experimental QUIC protocol to being Disabled.

8. Reset Chrome Flags

Here is what you should do in case you experimented with enabling various “beta-test” features. They are experimental and may not be fully optimized to work well with other default settings in the Google Chrome browser. We therefore recommend you to reset them all by going to Chrome Flags. To do this, follow the short list of steps below:

1. Open your browser and type chrome://flags into the search line.
2. Click on Reset all in the top right corner and Relaunch Chrome.
3. After restarting your browser, try to open the same problematic page again.

Summary

These eight methods should be enough to deal with the problem and browse the pages again. You can also try restarting your router, however, we do not think it is the problem in this case. If there is anything else deteriorating your user experience, feel free to surf our website for more articles related to other problems. Each day we publish new guides both about troubleshooting PC errors and removing various threats like unwanted programs or malware.