Quick Answers

What Is ERR_TUNNEL_CONNECTION_FAILED?

ERR_TUNNEL_CONNECTION_FAILED means the proxy refused or failed to open the HTTPS tunnel Chrome asked for, often because of authentication or blocked ports.

By Team of Monkeys Editorial Updated 1 min read Affiliate disclosure

This guide contains affiliate links to Geonode, Webshare and Rayobyte. If you buy through them we may earn a commission, at no extra cost to you.

What Is ERR_TUNNEL_CONNECTION_FAILED illustration: eRR_TUNNEL_CONNECTION_FAILED means the proxy refused or failed to open the HTTPS tunnel Chrome asked for, often because of authentication or blocked ports 3jdej38j4

The short answer

To load an HTTPS site through an HTTP proxy, Chrome sends a CONNECT request asking the proxy to open a tunnel. This error means the proxy said no, or the tunnel broke while opening.

Usual causes

  • Missing or wrong credentials (the proxy answered 407).
  • The provider blocks that site or port, for example banking or government sites on some residential networks.
  • The proxy only supports HTTP, not CONNECT.
  • A local firewall or antivirus intercepting the connection.
When the site notices 400 requests from the same IP (animated GIF) 3jdej38j4
When the site notices 400 requests from the same IP. GIF via GIPHY

Also known as

Tunnel connection failed, CONNECT failed, HTTPS proxy tunnel error.

Learn more

Affiliate disclosure: Team of Monkeys is an affiliate of Geonode, Webshare and Rayobyte. Links and banners marked as sponsored, and links to Geonode, Webshare and Rayobyte in the text, use our referral links, and we may earn a commission if you buy through them, at no extra cost to you. Our explanations and comparisons are written to be useful whichever provider you choose.

Editorial note: Proxy providers change their pools, features and prices often, so treat any figures here as typical ranges at the time of writing and confirm current terms with the provider before you buy.
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