Dec 02, 2025
Noviantika G.
5min Read
Encountering the ERR_SPDY_PROTOCOL_ERROR in Chrome can be irritating for website visitors. The message indicates the browser’s inability to connect to the web server using the SPDY protocol.
This error prevents a visitor from accessing a site, which may harm its web traffic volume.
Fortunately, solving the ERR_SPDY_PROTOCOL_ERROR is relatively easy. In this article, we will explain what it is, its possible causes, and seven ways to fix ERR_SPDY_PROTOCOL_ERROR.

| Error code | Connection refused |
| Error type | Network communication protocol error |
| Error causes | Network problem Incorrect SSH installation Wrong credentials Security system configuration |
SPDY was a pre-installed application-layer protocol on Google Chrome that utilizes the Transmission Control Protocol (TCP) to transport web content. Developed by The Chromium Projects, it was designed to reduce latency and increase loading speed.
But as the adoption of HTTP/2 became widespread, browsers, including Google Chrome, began ending support for SPDY. Currently, no modern browser supports SPDY, making it an obsolete protocol.
However, some users may still encounter SPDY-related errors and receive the ERR_SPDY_PROTOCOL_ERROR page.
In most cases, the ERR_SPDY_PROTOCOL_ERROR is a client-side issue. For instance, the site you are trying to visit may still use the older Hypertext Transfer Protocol (HTTP) connection, or your system is using an outdated browser or cache.

Before exploring the troubleshooting methods, try these quick fixes first:
If the error persists, try the following methods:
Using an outdated version of Google Chrome may trigger connectivity and performance issues. We recommend using the latest Chrome release to prevent issues that might contribute to the ERR_SPDY_PROTOCOL_ERROR.
Follow these steps to check your Chrome browser version and update it:
However, if a Google Chrome update is available, the system will automatically download and install it.
Making your browser version up to date can fix incompatibility and security issues. In most cases, this should solve the ERR_SPDY_PROTOCOL_ERROR problem.
If you only encounter the ERR_SPDY_PROTOCOL_ERROR message on a particular website, try visiting it using Chrome’s Incognito mode.
The Incognito mode will not retain cookies, site data, browsing history, and any information you enter into forms. However, bookmarks and downloads are still saved.
Here’s how to switch to Google Chrome’s Incognito mode:
If the problem persists, proceed to the next step.
The cache contains browsing history from all the web pages or URLs you have visited. Your browser data may be corrupted, causing the ERR_SPDY_PROTOCOL_ERROR issue. Clearing your browser’s cache is one possible way to solve the problem.
There are two options to choose from – the Basic tab and the Advanced tab. The former will retain saved passwords, auto-fill information, site settings, and hosted app data. The latter option will clear out all information from your browser.
If you can access the site after clearing the browser cache and cookies, it was probably the cause of the issue.
The ERR_SPDY_PROTOCOL_ERROR problem may occur because of harmful software installed on the computer. The best way to solve this issue is by running the Chrome Cleanup Tool. It scans the computer and removes unwanted applications interfering with your web browser.
Here’s how to run the Chrome Cleanup Tool:
A common solution to fix the ERR_SPDY_PROTOCOL_ERROR is flushing the SPDY sockets in Google Chrome. Here’s how to do it:
This should allow you to open the web page you are trying to visit. But if the issue persists, try the following method.
If you have tried all the methods above, but the ERR_SPDY_PROTOCOL_ERROR still occurs, the problem may be with the Domain Name System (DNS) configuration.
Try flushing DNS to clear IP addresses or other records from your DNS cache to fix it. Then, reboot the computer before reaccessing the same website for the best results.
Additionally, renewing the IP address may also solve the SPDY protocol error. Here’s how to do it on Windows:
ipconfig /release
ipconfig /renew
Flushing the DNS cache and renewing the IP address should solve the the SPDY protocol issue in most cases.
If you use Avast as your antivirus software, it may cause the ERR_SPDY_PROTOCOL_ERROR message. Although Avast and other antivirus applications protect against security threats, they may disrupt your network connection and block access to specific sites.
Remember that fully disabling antivirus software may expose your device to malware. So instead, we recommend applying the following configurations – turning off HTTPS scanning, disabling Web Shield, and adding exceptions.
Follow these steps to disable the HTTPS scanning feature:
Here’s how to turn off Web Shield:
Follow these instructions to add exceptions:
If disabling antivirus software fixes the issue, consider switching to a different security program.
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ERR_SPDY_PROTOCOL_ERROR may be a common problem for Google Chrome users. This error message usually occurs when the browser can’t support the SPDY protocol when connecting to the target web server.
The error has several possible causes. For example, the site you are trying to visit uses an HTTP connection, or your browser is outdated or has a cache issue.
This tutorial has covered seven methods to troubleshoot this error. We recommend trying all of them to solve the problem.
We hope this article has helped you solve ERR_SPDY_PROTOCOL_ERROR in Chrome. If you have any questions or suggestions, please leave them in the comments section below.
Here are the answers to some frequently asked questions about the error.
No, the ERR_SPDY_PROTOCOL_ERROR error can occur in any web browser that uses the SPDY protocol to establish secure connections, including Google Chrome, Mozilla Firefox, and Opera. However, the error is more commonly associated with Google Chrome, which was one of the first browsers to adopt the SPDY protocol.
To prevent ERR_SPDY_PROTOCOL_ERROR, try disabling the SPDY protocol in the web browser settings and using the traditional SSL/TLS protocol instead. Clearing browser cache and cookies, disabling browser extensions, and updating the browser to the latest version can also help resolve the error.