How to Fix DNS Error: Every Cause and Fix Step by Step

A DNS error stops you from loading websites — even when your internet connection appears active. These errors appear as DNS_PROBE_FINISHED_NXDOMAIN in Chrome, "Server not found" in Firefox, or "This site can't be reached" across browsers. Each message indicates that your device could not resolve the domain name into an IP address. This guide covers every cause and step-by-step fix for DNS errors on Windows, Android, iPhone, and Mac in 2026.

What Causes a DNS Error?

DNS errors have five main causes. Your ISP's DNS server may be down or unresponsive. Your local DNS cache may contain outdated or corrupted entries. The domain may be blocked by Kominfo or your ISP — in Indonesia, blocked domains return a DNS error rather than a block page on some ISP configurations. Your VPN or proxy may be misconfiguring DNS routing. Finally, the domain may genuinely not exist or may have expired. Identifying which cause applies to your situation determines which fix to try first.

Fix 1: Flush Your DNS Cache

Your system stores recent DNS lookups locally to speed up repeated visits. A corrupted or outdated cache entry causes DNS errors for sites that have changed their IP recently or whose DNS records have expired. Clearing the cache forces a fresh lookup from your DNS server.

Flush DNS on Windows

Open Command Prompt as Administrator (search cmd, right-click, Run as administrator) and run these commands in order:

ipconfig /flushdns
ipconfig /registerdns
ipconfig /release
ipconfig /renew

Restart your browser after running these commands and try loading the site again.

Flush DNS on macOS

Open Terminal and run:

sudo dscacheutil -flushcache; sudo killall -HUP mDNSResponder

Clear DNS on Android

Android does not have a direct DNS flush command. Instead, toggle Airplane Mode on for 10 seconds then off — this resets network connections and clears DNS cache. Alternatively, disconnect and reconnect from your Wi-Fi network.

Fix 2: Change to a Different DNS Server

Switching from your ISP's DNS server to a reliable third-party alternative resolves DNS errors caused by an unresponsive or malfunctioning ISP DNS. In Indonesia, IndiHome and Telkomsel DNS servers occasionally experience outages. Use Cloudflare (1.1.1.1 and 1.0.0.1) or Google (8.8.8.8 and 8.8.4.4) as alternatives. On Windows, go to Network Adapter Settings, right-click your connection, select Properties, click IPv4 Properties, and enter the DNS addresses manually. On Android 9+, go to Settings then Connections then Private DNS and enter one.one.one.one.

Fix 3: Restart Your Router

Your router maintains its own DNS cache. A simple restart clears this cache and often resolves DNS errors that cannot be fixed at the device level. Power off your router completely, wait 30 seconds, then power it back on. Wait 60 seconds for the router to fully restart before testing again. This is particularly effective for DNS errors affecting all devices on your network simultaneously.

Fix 4: Check if the Site Is Blocked in Indonesia

In Indonesia, Kominfo blocks thousands of websites. Some ISPs return a DNS error rather than a block page when a domain is on the blocklist. If the DNS error only affects one specific website — not multiple sites — it may be blocked rather than broken. Try accessing the same site with mobile data from a different ISP. If it loads on mobile data but not on your IndiHome connection, the site is likely blocked by your ISP's DNS. Changing to Cloudflare DNS (1.1.1.1) or using a VPN bypasses ISP DNS blocks.

Fix 5: Disable VPN or Proxy Temporarily

VPN or proxy configurations sometimes interfere with DNS resolution. Disconnect your VPN or proxy and try loading the site directly. If it loads without the VPN, the issue is with your VPN's DNS configuration. Check the DNS Leak Test while reconnected to your VPN — if your real ISP DNS is shown, the VPN is not routing DNS correctly. Reinstall the VPN app or contact support for assistance with DNS configuration.

Fix 6: Enable DNS-Over-HTTPS

DNS-over-HTTPS (DoH) encrypts DNS queries and sends them to a private resolver — bypassing both ISP DNS blocks and DNS server outages. In Chrome, go to Settings then Privacy and Security then Security, enable Use secure DNS, and select Cloudflare. In Firefox, go to Settings then General then Network Settings and enable DNS over HTTPS. This is a permanent fix that also improves privacy by preventing ISP DNS monitoring. After enabling, run the DNS Leak Test to confirm DNS is routing correctly.

Frequently Asked Questions