Is it possible to replicate the net::ERR_CONNECTION_RESET error at the client-side when making an API call or using a WebSocket?

I developed a live view application using Elixir, specifically a Phoenix application, and have been running it in the browser for an extended period of time. Occasionally, I encounter an error, such as net::ERR_CONNECTION_RESET, which completely removes the socket connection and prevents automatic reconnection. It appears as though the server is unable to transmit data to the client. To address this issue, I implemented error protection logic in my application. However, I would like to test the end-to-end flow of this error, but I am having difficulty reproducing the net::ERR_CONNECTION_RESET error in my Chrome browser.

ERR_CONNECTION_RESET is a TCP-level error, which means the other end of the TCP connection sends a TCP packet with the RST flag set to 1.

screenshot taken from Wikipedia

The most common cause I have experienced is China’s evil and notorious Great Fire Wall (GFW) that sits in the middle of the client and the server, and sends RST packet to both ends to fool them that the other end does not want to establish such connection. If that’s the case, your only choice is to use a proxy or a VPN to bypass GFW.


The net:ERROR_CONNECTION_RESET occurred due to a slow internet connection, which caused the app.js JavaScript file to fail to download properly. As a result, the live view phoenix app could not load and did not display the expected results.

To simulate the issue, I used a tool such as Fiddler or Wireshark to intercept or delay the connection. Specifically, I closed the network for localhost:5000/js/app.js, which prevented app.js from loading and triggered the aforementioned error