Internet Troubleshooter

Pick the problem you are having and follow the steps in order. Each step includes the fix and, where useful, a one-click test to confirm it worked.

Quick automatic check
InternetChecking…
LatencyChecking…
DNSChecking…
IPv6Checking…

  1. Check the lights on your modem/router. A red or blinking "Internet", "WAN", "DSL" or "Online" light means the line itself is down.
  2. Power-cycle in the right order: unplug the modem and router, wait 30 seconds, plug in the modem first and wait until it is fully online (2–3 minutes), then the router.
  3. Check for an outage on your ISP's status page or app, ideally from your phone's mobile data.
  4. Check cables: reseat the coax, fibre or phone cable and the Ethernet cable between modem and router.
  5. Log in to the router (often 192.168.1.1 or 192.168.0.1) and see whether it has a WAN IP address. If its WAN address is blank or in 169.254.x.x, the ISP connection is down.
  6. If nothing helps, contact your ISP. Note which lights are on and that you already restarted the equipment.

  1. Test another device. If others work, the problem is this device; if none work, follow "No internet on any device".
  2. Check the IP address. An address starting with 169.254 means the device did not get one from the router (DHCP failure). Use the IP type checker if unsure.
  3. Forget and rejoin the network, re-entering the password.
  4. Renew the IP and reset the network stack on Windows (run as administrator): 
    ipconfig /release
ipconfig /renew
ipconfig /flushdns
netsh winsock reset
    then restart. On macOS: System Settings → Network → Wi-Fi → Details → TCP/IP → Renew DHCP Lease.
  5. Disable VPNs, proxies and security software temporarily.
  6. Hotel or café Wi-Fi? Open http://neverssl.com to trigger the sign-in page.

  1. Measure first: run our ping and jitter test, then a speed test, once on Wi-Fi and once wired if possible.
  2. Find the bandwidth hog: pause cloud backups, game updates, torrents and 4K streams on other devices.
  3. Improve Wi-Fi: move closer, use the 5 GHz or 6 GHz band, keep the router high and central, and change the channel if neighbours are crowding yours.
  4. Restart the router and update its firmware.
  5. Compare with your plan. If wired speeds are far below what you pay for at several times of day, contact your ISP.
  6. Old hardware: routers and adapters older than Wi-Fi 5 (802.11ac) often cap real-world speeds.

  1. Wired or wireless? If drops happen only on Wi-Fi, it is interference or range: change channel, move the router, or add a mesh node.
  2. Run a long ping to your router and to the internet at the same time (ping -t 192.168.1.1 and ping -t 1.1.1.1 on Windows). Losses to the router point at your Wi-Fi; losses only to the internet point at the ISP line. See how to use ping and traceroute.
  3. Check the modem log for repeated resyncs or "T3/T4 timeouts" (cable), which indicate a line fault only the ISP can fix.
  4. Disable power saving on the network adapter (Windows Device Manager → adapter → Power Management).
  5. Overheating: make sure the router has airflow.

  1. Is it down for everyone? Check with Is It Down?.
  2. Try a private window to rule out extensions and cached data, then clear the site's cookies.
  3. Flush DNS (ipconfig /flushdns) and compare DNS records with what your computer resolves using nslookup example.com.
  4. Certificate warnings? Check your device's date and time, then test the site with the SSL checker.
  5. Blocked by your network? Parental controls, school/work filters or ISP blocks can stop certain sites. Try mobile data to compare.

  1. Check the spelling and whether the domain still exists with WHOIS.
  2. Flush DNS caches: Windows ipconfig /flushdns; macOS sudo dscacheutil -flushcache; sudo killall -HUP mDNSResponder; Chrome chrome://net-internals/#dns.
  3. Switch to a public resolver such as 1.1.1.1 or 8.8.8.8 in your router or device settings.
  4. Recently changed DNS for your own site? Watch the DNS propagation checker, and test DNSSEC: a broken DNSSEC setup causes failures only on validating resolvers.

  1. Measure jitter and packet loss with the ping test. Jitter above about 30 ms or any packet loss causes stutter.
  2. Use Ethernet for consoles and PCs; Wi-Fi adds variable delay.
  3. Enable QoS / Smart Queue Management on the router to stop uploads from swamping your connection (bufferbloat).
  4. Choose nearby game servers, and avoid VPNs that route you far away.
  5. Strict or moderate NAT type? Check whether you are behind carrier-grade NAT and test forwarded ports with the port checker.

  1. Confirm your public IP on the home page. If it changes often, use dynamic DNS.
  2. Check for CGNAT: if the router's WAN address is in 100.64.0.0/10 or private space, inbound connections cannot reach you. Ask your ISP for a public IPv4 address, or use IPv6 or a tunnel/VPN service.
  3. Set up port forwarding to the device's fixed local IP, then confirm with the open port checker.
  4. Allow the port in the device's own firewall, and make sure the service is running.
  5. Prefer a VPN (such as WireGuard) over exposing cameras and NAS admin pages directly to the internet.

  1. Check the domain's mail servers with MX lookup.
  2. Validate SPF, DKIM and DMARC with the email authentication checker; missing records are the most common cause.
  3. Check the sending IP's reputation with the blacklist check and confirm it has valid reverse DNS.
  4. Read the bounce message: codes like 550 5.7.1 usually name the exact policy that rejected the mail.

A systematic way to fix internet problems

Most connection problems can be solved by working from the closest component outward: your device → your Wi-Fi or cable → your router → your modem and ISP line → the wider internet → the website itself. Testing each layer in turn tells you exactly where things break, so you fix the right thing instead of guessing. The quick check above already tells you whether you can reach the internet, how responsive your connection is, whether DNS works and whether you have IPv6.

The five commands every troubleshooter should know

CommandWhat it tells you
ipconfig /all · ip addrYour local IP, gateway (router) and DNS servers.
ping 192.168.1.1Whether your device can reach the router.
ping 1.1.1.1Whether you can reach the internet without needing DNS.
nslookup example.comWhether DNS resolution works.
tracert · tracerouteWhere along the path the connection slows or stops.

If ping 1.1.1.1 works but ping example.com fails, you have a DNS problem. If pinging the router fails, the problem is inside your home network. For a detailed walkthrough, read How to fix common internet connection problems.

Frequently asked questions

Why does restarting the router fix so many problems?

It clears memory leaks and stuck connection tables, renews the connection with your ISP and often gets a fresh IP address.

How do I know if my ISP is the problem?

If a device wired directly to the modem still has no connection or very poor performance after a restart, and the modem's status lights or log show errors, the fault is on the ISP side.

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