--- title: "ERR_CONNECTION_CLOSED: What It Means and How to Fix It" description: "ERR_CONNECTION_CLOSED means the server closed the connection without sending a page. See the usual causes, such as a TLS or port mismatch, and the fixes." url: https://uptrack.app/errors/err-connection-closed --- ERR\_CONNECTION\_CLOSED

# ERR\_CONNECTION\_CLOSED: what it means and how to fix it

ERR\_CONNECTION\_CLOSED means the server closed the connection before it sent a page. Unlike a reset, the connection ends in an orderly way, so the cause is often a setting: an HTTPS request to a plain HTTP port, a TLS mismatch, or a rule in a proxy or firewall. You may also see - “This page isn’t working. The server unexpectedly closed the connection” (Chrome) ## Common causes 1. 1 An HTTPS request goes to a port that serves plain HTTP, or the other way round, and the server closes the connection. 2. 2 The browser and the server do not share a TLS version or a cipher, so the handshake ends. 3. 3 A proxy, a load balancer or a firewall closes connections that match a rule, or that exceed a limit. 4. 4 The server is overloaded and closes new connections, or its process has hit a limit. 5. 5 A VPN, a proxy or a security program on the device interferes with the connection. ## If you are visiting the site: how to fix it 1. 1 Check that the address starts with the right scheme and port: https:// for secure sites. Try http:// only if you know the site is not secure. 2. 2 Try another network and another browser. 3. 3 Turn off a VPN and a proxy, then clear the browser cache and cookies for the site. 4. 4 Check that the date and time of your device are right, because a wrong clock breaks secure connections. ## If you run the site: what to check 1. 1 Check what answers on the port: a TLS server on 443, and plain HTTP on 80. A site that listens for HTTP on 443 closes every HTTPS connection. 2. 2 Check the TLS versions and the ciphers of the server. Allow TLS 1.2 and TLS 1.3. 3. 3 Check the rules and the limits of the proxy, the load balancer and the firewall in front of the site. 4. 4 Check the load and the limits of the server: open file limits, worker counts and memory. ## Check it with free tools - [SSL checkerCheck that the port speaks TLS and see the certificate.](https://uptrack.app/tools/ssl-checker) - [Is a website down?Check the site from several locations.](https://uptrack.app/tools/is-website-down) ## Frequently asked questions What does ERR\_CONNECTION\_CLOSED mean? The browser connected to the server, and the server closed the connection before it sent a page. The server decided to close it, or something between you and the server did. What is the difference between ERR\_CONNECTION\_CLOSED and ERR\_CONNECTION\_RESET? Both mean the connection ended too early. A reset is a sudden end, often caused by a crash or a rule that cuts the connection. A close is an orderly end, so it points more often to a setting such as the wrong port or a TLS mismatch. Why does ERR\_CONNECTION\_CLOSED appear on a new HTTPS site? The server may not serve TLS on port 443 yet, the certificate may not be set up, or a proxy in front may speak another protocol. Check the port with an SSL checker. How do I fix ERR\_CONNECTION\_CLOSED as a visitor? Check the address, try another network and browser, turn off a VPN or proxy, and check the clock of your device. If the site fails everywhere, only the site owner can fix it. ## Know about it before your visitors do Uptrack checks your site on a schedule from several locations and alerts you when it stops answering, so you hear about it from an alert and not from a customer. [See plans](https://uptrack.app/pricing) from $3/mo · 30-day money-back guarantee ## Other browser and DNS errors - [DNS\_PROBE\_FINISHED\_NXDOMAIN](https://uptrack.app/errors/dns-probe-finished-nxdomain) - [ERR\_NAME\_NOT\_RESOLVED](https://uptrack.app/errors/err-name-not-resolved) - [DNS server not responding](https://uptrack.app/errors/dns-server-not-responding) - [ERR\_CONNECTION\_REFUSED](https://uptrack.app/errors/err-connection-refused) - [ERR\_CONNECTION\_RESET](https://uptrack.app/errors/err-connection-reset) - [ERR\_SSL\_PROTOCOL\_ERROR](https://uptrack.app/errors/err-ssl-protocol-error) - [NET::ERR\_CERT\_AUTHORITY\_INVALID](https://uptrack.app/errors/your-connection-is-not-private)