LightAtom

Why Is My Internet Not Working? Find the Cause in 60 Seconds

Run the check below to see whether the problem is your connection, DNS or something slower, then follow the steps for that cause.

Websites won't load, apps say you're offline, or everything is painfully slow, and you don't know whether it's your device, the router or your provider.

  • Pages don't load or show errors like “This site can't be reached”.
  • Wi-Fi shows connected, but nothing works.
  • Only some sites or apps work.
  • The connection drops in and out.

Quick fix

  1. Restart your router and modem: unplug them for 30 seconds, plug the modem in first, wait for its lights, then the router.
  2. Check other devices: if they're offline too, it's the router or your ISP. If only one device fails, it's that device.
  3. Run the check below: it tests the connection without DNS, then with DNS, then latency, and points you to the right fix.

Why it happens

Router or modem needs a restart, or lost its connection to the ISP.Most likely
Wi-Fi problem on one device: weak signal, wrong network, stale settings.Most likely
DNS server not responding, so names don't resolve.Sometimes
ISP outage in your area.Sometimes
VPN, proxy or security software blocking traffic.Sometimes
Unpaid bill, data cap or a captive portal that needs logging in.Rarely

Fixes

  1. If the check says you're not connected

    1. Restart the router and modem. Check the modem's internet or WAN light.
    2. On your Mac, turn Wi-Fi off and on, and make sure you're on your own network.
    3. Check your ISP's outage page or app on mobile data.

  2. If the internet works but DNS doesn't

    1. Set public DNS servers: System Settings › Network › Wi-Fi › Details › DNS › add 1.1.1.1 and 8.8.8.8.
    2. Flush the cache: sudo dscacheutil -flushcache; sudo killall -HUP mDNSResponder.

  3. If it's connected but slow

    1. Pause big downloads, backups and cloud sync, then run the bufferbloat test.
    2. Move closer to the router or use Ethernet.

  4. If only some sites fail

    1. Turn off VPNs and content blockers; try a private window.
    2. Check the site on mobile data: if it fails there too, the site is down.

Still not working?

If the modem shows no internet light after a restart, or every device is offline for more than 15 minutes, call your ISP: the line or their network is down. Mention the lights on the modem; it speeds up their diagnosis.

Check it now

Takes about 5 seconds.

See it in the app

When the internet is back, LightAtom's connections view shows which app is using the connection, useful when “slow internet” is really one app uploading.

Frequently asked questions

Why is my internet not working but Wi-Fi is connected?

Wi-Fi connects you to the router, not the internet. The router may have lost its connection to your ISP, or DNS may be failing. Restart the router and run the check above.

How do I know if my ISP is down?

If every device on your network is offline after a router restart, and the modem's internet light is off or red, the ISP is likely down. Check its status page using mobile data.

Why does only one device have no internet?

The problem is that device: wrong network, an old IP setting, a VPN or proxy, or software blocking traffic. Forget and rejoin the Wi-Fi network as a first step.

Does restarting the router really help?

Often. It clears memory, renews the connection to your ISP and reassigns addresses. It's the most effective first step for home connections.

Related

LightAtom team

The people who build LightAtom, a network monitor for macOS.