Why does my internet keep cutting out?

Acutis · plain-English network help · updated June 2026

When your internet keeps cutting out

When the internet keeps cutting out — dropping every few minutes, then coming back on its own — the cause is almost always physical: a cable, a piece of hardware, or the line coming into your home. Unlike WiFi-only problems, internet that cuts out for every device at once points upstream, to the modem and the connection between your home and your provider. This guide helps you isolate where the drop is happening and fix it.

The most common reasons the internet keeps cutting out:

• A loose or damaged coax / fiber / DSL cable at the wall or the modem.
• An overheating or failing modem that resets itself.
• A weak or noisy line from your internet provider.
• DNS problems that make sites fail to load even when the line is up.
• A failing router sitting between the modem and your devices.

Step 1: Watch the modem lights

Your modem's lights tell the story. When the internet drops, look at the modem:

• If the online / internet light goes out or starts blinking when you lose connection, the drop is between the modem and your provider — a line or signal problem.
• If the modem lights stay solid and steady but you still lose connection, the problem is downstream — your router, WiFi, or a single device.

This one observation splits the problem in half and saves you from chasing the wrong end.

Step 2: Check the cables

Loose and corroded cables are the single most common cause of intermittent drops, and the easiest to fix.

• Hand-tighten the coax connector at the back of the modem and at the wall plate. It should be finger-tight, not just resting on the threads.
• Inspect the cable for kinks, crimps, or chew marks. A damaged cable causes random drops that come and go with temperature and movement.
• Remove any splitters on the line if you can. Each splitter weakens the signal and adds a point of failure.
• For DSL, make sure a filter is on every phone jack sharing the line.

Step 3: Rule out an overheating modem

A modem that drops connection after it has been running a while, then recovers once it cools, is overheating. Modems crammed into a cabinet or stacked on top of other warm gear are prone to this.

• Move the modem to an open, ventilated spot and make sure its vents are clear.
• If the modem is more than five years old and resets frequently, it may be failing. Many providers will swap a rented modem for free, or you can buy your own.

Step 4: Test for an ISP line problem

If the modem's internet light flickers during drops, the issue is likely your provider's line. To gather evidence:

• Log into the modem's status page (often 192.168.100.1 for cable modems) and look at the signal levels and the error log. A long list of "T3 timeouts" or many uncorrectable errors confirms a line problem.
• Note the times the drops happen. A pattern (every evening, after rain) is strong evidence to give your provider.
• Call your provider with this information. Ask them to check the signal to your modem and, if needed, send a technician to inspect the line.

Step 5: Rule out DNS

Sometimes the connection is fine but websites stop loading, which feels like the internet cutting out. That is often a DNS problem — the system that turns names like example.com into addresses. A quick test: when a site won't load, see if a numeric address works. If it does but names don't, switch your DNS to a fast public resolver such as 1.1.1.1 (Cloudflare) or 8.8.8.8 (Google), and clear the cache:

• Windows: ipconfig /flushdns
• Mac: sudo dscacheutil -flushcache

Step 6: Isolate the router

If the modem is solid but devices still drop, the router is the suspect. Test it directly: plug a computer into the modem (or into the router's main port) with an Ethernet cable.

• If the wired connection is stable while WiFi keeps dropping, the router's wireless side or the WiFi signal is at fault.
• If even the wired connection drops, reboot the router, update its firmware, and if it keeps failing, replace it.

Put it together

Intermittent internet is a process of elimination: watch the modem lights, tighten and inspect the cables, rule out heat, check the line, then work your way down through DNS and the router. The goal is to know which link in the chain is breaking before you spend money or wait on a technician.