Chrome shows err_tunnel_connection_failed when a proxy or DNS server drops the request before it reaches the website. The site itself is often online.
Your connection tends to work too, since other tabs and apps keep loading. The fix sits in Windows or macOS settings, not inside Chrome. Four checks cover nearly every case.
How to fix err_tunnel_connection_failed in Chrome: start with the proxy
Clear Chrome’s cached files first. Press Ctrl+Shift+Delete (Cmd+Shift+Delete on a Mac), pick All time, tick cached images and files, and reload.
Still blocked? Work through the fixes in this order. Each one targets a different layer, so stop once the page loads.
- Proxy settings: the most common cause, so check it first
- Network reset: clears the IP lease and local DNS cache
- DNS server: replaces a resolver that fails to answer
- Chrome reset: the last step once the network checks out
What does err_tunnel_connection_failed mean?
A tunnel is a secure path that carries data between your device and a server. Chrome raises this error when it cannot build that path through a proxy or other middle server.
In most cases, the proxy or DNS server cannot resolve the address you typed. That explains why one site fails while the rest of the web loads.
The exact code belongs to Chrome. Its on-screen hint says the site may be down or moved, but that text rarely matches the real fault.
A page claiming you have no connection at all is a separate problem, covered in our guide on why Chrome thinks you are offline.
Four fixes for err_tunnel_connection_failed on Windows and macOS
Chrome has no proxy or DNS menu of its own. It reads both from the operating system, so every change below happens at system level.
Fix 1: Check the proxy in LAN settings
On Windows, press Win+R, type inetcpl.cpl and press Enter. Open the Connections tab, then LAN settings.
An address under Proxy server means Windows sends traffic through a fixed proxy. Tick “Automatically detect settings” and reload. If the error stays, untick both options to browse with no proxy.
Corporate proxies that inspect HTTPS traffic can also cause certificate name mismatch warnings, so note any address you find before removing it.
On macOS, open System Settings > Network, pick the active service, then choose Details > Proxies. Switch the proxies off and test again.
The same system-level rule holds when you run Chrome on Ubuntu. Set Settings > Network > Network Proxy to Disabled on GNOME.
Fix 2: Flush DNS and reset Winsock
This step assigns a fresh IP address and empties the local DNS cache. Open Command Prompt as administrator. Run each command and wait for it to finish:
- ipconfig /flushdns
- nbtstat -R
- netsh int ip reset
- netsh winsock reset
Restart the computer, then open Chrome. If the message returns, DNS is the next suspect.
macOS has no single reset command. Remove the Wi-Fi or Ethernet service under Network, then add it back.
Fix 3: Switch to Cloudflare, OpenDNS or Google Public DNS
Windows uses your ISP’s DNS server unless told otherwise. A faulty resolver can also trigger err_name_not_resolved in Chrome, so the two errors often share a fix.
Open Advanced network settings > More network adapter options (Change adapter options on Windows 10). Right-click the active connection and pick Properties.
Select Internet Protocol Version 4 (TCP/IPv4) and click Properties. If DNS is on automatic, enter a public resolver such as 1.1.1.1, 208.67.222.222 or 8.8.8.8, plus an alternate.
Already on a custom DNS? Switch back to automatic. A page that opens afterwards points to a short outage at your old resolver.
Fix 4: Restore Chrome’s default settings
Open Settings > Reset settings > Restore settings to their original defaults. Chrome turns off extensions and clears temporary data. Bookmarks stay.
Then load the same site in Firefox or Edge. A failure there too clears Chrome of blame. Go back over the proxy and DNS steps one at a time.
Can a VPN trigger err_tunnel_connection_failed?
Yes. A VPN routes traffic through its own server, and a dead exit node breaks the tunnel the same way a bad proxy does.
Disconnect the VPN and reload. If the page opens, pick a different server or protocol inside the VPN app.
Some VPN apps leave a proxy entry behind after a crash. Recheck LAN settings once the VPN is off. A stuck VPN can also leave you staring at a blank net::err_empty_response page.
It works the other way too. When your ISP’s proxy or DNS is at fault, switching a VPN on can route around it.
407 Proxy Authentication Required and errors similar to err_tunnel_connection_failed
Only Chrome prints this exact code. Proxy and DNS faults still show up in every browser, under other names.
- DNS Server Not Responding appears in Chrome, Safari, Firefox and Edge when the resolver sends no reply.
- 407 Proxy Authentication Required means the proxy rejected missing or wrong login details.
- err_quic_protocol_error is a separate Chrome fault, and our guide to clearing QUIC handshake failures covers it.
Changing DNS or proxy settings, or turning on a VPN, resolves most of these. If the error hits your own website, your host’s support team can trace it from the server side.
FAQs
How do I fix err_tunnel_connection_failed?
Clear Chrome’s cache, then turn off the proxy under inetcpl.cpl > Connections > LAN settings. If the error stays, flush DNS, reset Winsock, switch to a public DNS server, and reset Chrome last.
Is err_tunnel_connection_failed a virus?
No. The code reports a failed proxy or DNS connection. Malware can change proxy settings and cause it, so run a scan if an unknown proxy address keeps coming back.
Why does err_tunnel_connection_failed only show in Chrome?
The wording comes from Chromium, so Edge and Opera can show it too. Firefox and Safari report the same proxy or DNS fault under different messages.
What fix does Reddit suggest for err_tunnel_connection_failed?
Reddit threads often trace it to a VPN that dropped and left its proxy entry behind. Disconnecting the VPN and clearing that proxy setting restores browsing in most reports.
What should I post on Reddit about err_tunnel_connection_failed?
List your operating system, Chrome version, any VPN or proxy in use, and which fixes you already tried. Helpers on r/techsupport and r/chrome can then narrow the cause faster.
