---
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)