Failed-error-during-websocket-handshake-connection-header-is-missing Review
: Force websocket transport: io('url', { transports: ['websocket'] }) .
Here are the most common solutions based on your infrastructure: 🚀 Nginx Configuration Fix
Which or server framework are you currently using to host this application? Copied to clipboard ☁️ Cloud Providers & Load
RewriteCond %{HTTP:Upgrade} websocket [NC] RewriteCond %{HTTP:Connection} upgrade [NC] RewriteRule /(.*) ws://localhost:8080/$1 [P,L] Use code with caution. Copied to clipboard ☁️ Cloud Providers & Load Balancers
The error occurs when a client tries to establish a WebSocket connection, but a network intermediary (like a reverse proxy or load balancer) strips out the required HTTP headers needed to upgrade the connection from standard HTTP to WebSockets . By default, Nginx does not do this
location /ws { proxy_pass http://your_backend_server; proxy_http_version 1.1; proxy_set_header Upgrade $http_upgrade; proxy_set_header Connection "upgrade"; } Use code with caution. Copied to clipboard 🕸️ Apache Configuration Fix
If you are using Nginx as a reverse proxy, you must explicitly tell it to forward the Upgrade and Connection headers. By default, Nginx does not do this. Add or update your location block in your nginx.conf file: proxy_set_header Upgrade $http_upgrade
Ensure mod_proxy and mod_proxy_wstunnel are enabled. Use a RewriteRule in your VirtualHost to pass WebSocket traffic: