How To Fix the Err_quic_protocol_error in Google Chrome

Jamie Read more May 9, 2021

Do you occasionally see the Err_quic_protocol_error in Google Chrome? Are you occasionally unable to surf sites using Chrome but using other browsers is okay? The Err_quic_protocol_error is an intermittent error that can often be troublesome to troubleshoot, but TechJunkie has the answer. Here is how to fix the Err_quic_protocol_error in Google Chrome.

How To Fix the Err_quic_protocol_error in Google Chrome

Google Chrome has to be one of the most stable browsers out there. It has been around for years and is developed by a company in whose interest it is for you to be able to surf quickly and safely. While overtaken by Firefox Quantum in terms of speed and features, Chrome is still used by millions and is still the base for other browsers who use Chromium.

The release version of the browser is very stable, but the Chrome browser comes with a variety of experimental features that often aren’t supported by various devices and websites. Remember, often times features have to be rolled back to prevent issues, such as a change to autoplay audio that accidentally muted online browser games. While rare, these things do happen and are the price we pay for a cutting edge browser.

Fixing the Err_quic_protocol_error

A quick word on those websites that offer to fix this error with a download. It doesn’t need one and is a very straightforward fix. While I name no names, websites offering a one tool fixes all panacea for Chrome, Windows or any program is selling snake oil. Even if they offer a patch specifically for this error, you don’t need one so use those sites with care.

The QUIC protocol is actually quite interesting but rather than bury the headline, I’ll show you how to fix the error before discussing it.

The Err_quic_protocol_error seems to happen on fiber networks with fast routers. I have no idea why it happens but slower ADSL or ADSL2 routers don’t seem to have this problem. Either way, here is how to fix it.

Open Chrome, type ‘chrome://flags’ into the URL bar and hit Enter.
Search or locate ‘Experimental QUIC protocol’.
Select the box to the right and change the setting from Default to Disabled.
Restart Chrome for the change to take effect.

This should be enough to fix the Err_quic_protocol_error in most situations. I have seen a couple where it didn’t and the only option there was to uninstall and then reinstall Chrome. If you need to do that, here’s how. Once you have reinstalled Chrome, recheck the QUIC flag as above to stop it happening again.

On Windows:

Open the Windows Start menu and find Google Chrome.
Right click the entry and select Uninstall.
Download a fresh copy from here.
Select the installer and run to install.

On Mac:

Right click the Chrome icon in your Dock and select Quit.
Use Finder to locate Chrome and drag the icon to the Trash.
Download a fresh copy and install.

If you do have to reinstall, this method should keep all your favorites and settings. It replaces the core Chrome files with new ones and will pick up bookmarks and everything else from elsewhere on your computer. Now Chrome should work fine without the Err_quic_protocol_error.

The QUIC protocol

The Quick UDP Internet Connections (QUIC) protocol is an experimental network transport mechanism being worked on at Google. The idea is to eventually replace the TCP protocol. By shrinking the overhead of TCP and multiplexing the streams rather than doing them in succession QUIC is destined to be much, much faster than TCP.

A typical TCP connection involves a single stream and lots of back and forth between your browser and the destination. There is a handshake, acknowledgment, synchronization, setup and initial data transfer before the first real data packet is sent. This causes a delay and introduces the potential for bottlenecks. If one TCP packet gets stuck, the others get stuck behind it causing lag.

QUIC on the other hand has been designed for speed. Rather than the multiple setup messages of TCP, QUIC does it in a single message. QUIC also uses UDP multiplexing which enables further messages to pass even if one is stuck. It also includes built-in congestion control for maximum efficiency.

Another feature of QUIC is error control. It can handle lost packets with ease and manages loss with speculative retransmission. TCP uses congestion avoidance but this is limited to faster or less congested networks. Slower or unreliable networks cause TCP headaches. QUIC has its own system of boundaries and packet pacing to help handle delayed or lost packets.

QUIC has been in development for six years now and still isn’t finished. Google are the driving force behind it but apparently less than 1% of web servers support it. If you want to learn more about QUIC, this resource is excellent.