Firefox: Hmm. We’re having trouble finding that site. / Server not found (DNS_PROBE or NS_ERROR_UNKNOWN_HOST)
Firefox could not resolve the website’s hostname to an IP address — a typo, a DNS problem or no internet.
Hmm. We’re having trouble finding that siteServer not foundFirefox can’t find the server atWe can’t connect to the server at Meaning
This is Firefox's version of DNS_PROBE_FINISHED_NXDOMAIN. Check the address, then whether other sites load. If only one site fails, its DNS records may be missing; if all fail, check connectivity, DNS servers and "DNS over HTTPS" settings.
Common causes
- Typo in the address or a non-existent domain
- No internet connection
- Broken DNS server from the ISP/router
- DNS over HTTPS (Firefox default in some regions) blocked by the network
- VPN/proxy overriding DNS
⚡ Quick fix
- Check spelling and try again
- Test another site and another network
- Try different DNS (1.1.1.1) or turn off DNS over HTTPS in Settings
Detailed fix by platform
Firefox
- Settings → General → Network Settings → Settings… → untick "Enable DNS over HTTPS" for a test
about:networking#dnsshows resolver activity
Windows
ipconfig /flushdns, then set DNS to 1.1.1.1 and 8.8.8.8
How to diagnose
- Scope — One site or all sites?
- DNS — Does nslookup resolve?
- DoH — Secure DNS blocked by network?
🔧 Still not fixed?
Many errors look alike. If the steps above didn’t solve it, one of these is probably what you’re facing:
Similar errors
Most viewed in Browser
Other ways to find it
Where this error sits
Origin: On your device. Errors that are often confused with or caused by this one (click to open):
🧠 Still stuck? Analyze your error
Paste the full message, response headers or stack trace — we'll detect the platform and point to the most likely cause.
💬 What worked for others
No tips yet — did something else fix this for you?
Share what worked for you
Tips are checked by an editor before they appear. Links are removed.
Report a correction or suggest an improvement
Last updated 15 Oct 2026