DNS_PROBE_FINISHED_BAD_RESPONSE

What’s actually happening

One specific site (or all sites) fails to load in Chrome while the connection icon still shows you're online. Other apps may work fine, which points the finger at name resolution rather than the link itself. Reloading doesn't help; the error comes back instantly. Chrome's async DNS resolver got a response packet it couldn't make sense of, so it threw the whole answer away.

Common causes

• A buggy or overloaded ISP/router resolver returning truncated or garbage DNS responses
• A captive portal or filtering DNS appliance injecting redirect answers Chrome rejects
• An ad-blocking or privacy extension rewriting DNS-over-HTTPS responses into something invalid
• A stale or poisoned entry in the OS or Chrome DNS cache
• Router firmware bug mangling responses, common after a long uptime

How to fix it

1. Flush the OS and Chrome DNS cachesOn Windows run `ipconfig /flushdns`; on macOS run `sudo dscacheutil -flushcache; sudo killall -HUP mDNSResponder`. Then open chrome://net-internals/#dns and click 'Clear host cache', and chrome://net-internals/#sockets to flush sockets.
2. Switch to a known-good resolverSet DNS to 1.1.1.1 / 1.0.0.1 (Cloudflare) or 8.8.8.8 / 8.8.4.4 (Google) in your OS network settings or router. If the bad response was coming from your ISP resolver, this fixes it immediately.
3. Test in an incognito window with extensions offOpen an Incognito window (Ctrl/Cmd+Shift+N). If the site loads, an extension is rewriting responses. Re-enable extensions one at a time, ad blockers and VPN/proxy add-ons first, to find the culprit.
4. Check Chrome's Secure DNS settingchrome://settings/security -> 'Use secure DNS'. Toggle it off, or set it to a specific provider. A misbehaving DoH endpoint returns answers the resolver can't parse.
5. Reboot the routerPower-cycle the router for 30 seconds. Firmware that has been up for weeks frequently starts returning corrupt DNS until restarted; if it recurs, update the firmware.