Is My Internet Down? How to Tell If It's Your ISP
Is your internet down, or is it your router or device? A five-minute check with modem lights, ping tests and WAN status, plus how to confirm an ISP outage and what to do next.
When nothing loads, the real question is not "is the internet down?" but where it stopped working: on your device, on your home network, or at your internet service provider. Each one has a different fix, and guessing wrong wastes time. Restarting a router will not repair a cut fiber, and waiting for the ISP will not fix a laptop with a broken network setting. This guide walks through a five-minute check that tells the three apart, then covers how to confirm an ISP outage, what usually causes one, and what to do while you wait.
Outages are more common than most people assume. In the week of August 31 to September 6, 2026, ThousandEyes recorded 245 ISP outages in the United States alone, a 21 percent jump on the week before, according to Network World's weekly outage report. That same week included a 57-minute AT&T disruption on September 6 and a multi-country incident at the backbone carrier Cogent on September 2. Most events like these are short and local, which is exactly why a quick, structured check beats refreshing a browser tab and hoping.
The 60-Second Answer
Three questions settle most cases before you touch a single cable:
- Does any other device work? If your phone on the same WiFi loads pages but your laptop does not, the internet is fine and the laptop is the problem.
- What do the modem lights say?A red, orange or blinking "Internet", "Online" or "LOS" light points to the line or the ISP. Normal steady lights point back inside your home.
- Is your ISP reporting a problem?Check the provider's app or status page over mobile data. If it lists an outage for your area, stop troubleshooting and wait for the repair.
If every device fails, the modem shows a fault and the ISP confirms an outage, the internet really is down for you and there is nothing to fix at home. If the answers are mixed, the five steps below narrow it down.
Step 1: Is It One Device or Every Device?
Start with a second device on the same network. A phone with WiFi on and mobile data switched off is the easiest test, because it uses exactly the same router and ISP as your computer.
- Only one device fails. The connection is fine. The fault is on that device: its WiFi adapter, network settings, a VPN client, security software or a browser setting. Skip ahead to the fixes on your side.
- Only WiFi devices fail, wired ones work.The router's wireless side is the problem, not the ISP. Restart the router, then work through interference and band issues in the WiFi guide.
- Every device fails, wired and wireless. The fault is at the router, the modem or somewhere beyond them. Keep going.
If you only have one device, swap the connection instead. Turn on your phone's hotspot and join it from the laptop. If the laptop works over the hotspot, the laptop is healthy and the home connection is the suspect. The personal area network guide compares USB, Bluetooth and WiFi tethering if you need a stable backup link.
Step 2: Read the Modem and Router Lights
The modem, fiber terminal or 5G gateway is the box that talks to your ISP, and its lights are the quickest way to see whether the line itself is up. Labels and colors vary by model, so check the sticker or manual, but the patterns are similar across brands:
- Cable modems (DOCSIS).The Downstream and Upstream lights blink while the modem searches for the ISP's channels and turn solid once it locks on. The Online light turns solid when the ISP has registered the modem. A modem that keeps cycling through blinking lights cannot hear the ISP's network at all.
- Fiber terminals (ONT).A solid PON light means the optical link is up. A red LOS (loss of signal) light means no light is reaching the terminal, either because a fiber cable in your home is disconnected or damaged, or because of a fault on the ISP's side. Do not unplug the fiber cable or look into its connector.
- DSL modems. The DSL or Sync light blinks while the modem trains with the exchange and stays solid once it is synced. A solid DSL light with the Internet light off usually means the line works but the login session (PPPoE) failed.
- 4G and 5G home gateways. Check the signal indicator. A gateway with full signal but no service points to the carrier, while one with weak or no signal may just need moving closer to a window.
If the modem looks healthy, look at the router. Combined modem-router units have a single set of lights. With separate boxes, the router's Internet or WAN light shows whether it is getting a connection from the modem. A red or amber WAN light on the router while the modem looks normal points to the router or the cable between the two boxes.
Step 3: Test the Connection Layer by Layer
Lights tell you whether the line is up. A few ping commands tell you how far your traffic actually gets. Open Command Prompt on Windows or Terminal on macOS and Linux and run these in order:
# 1. Find your router (the default gateway)
ipconfig Windows: read "Default Gateway"
route -n get default macOS
ip route | grep default Linux
# 2. Can you reach the router?
ping 192.168.1.1
# 3. Can you reach the internet by IP address, without DNS?
ping 1.1.1.1
# 4. Do names resolve?
nslookup example.com
ping example.comReplace 192.168.1.1 with the gateway address from the first command; the guide to finding your router IP lists the common defaults. On macOS and Linux, add -c 4 so ping stops after four attempts, for example ping -c 4 1.1.1.1.
Read the results from the top down. The first test that fails shows where the break is:
- The router does not answer. The problem is inside your home network: the WiFi connection, a cable, or the router itself.
- The router answers, 1.1.1.1 does not. Your home network is fine, but nothing gets past the modem. That is a modem, line or ISP problem.
- 1.1.1.1 answers, but names fail.The connection works and DNS is broken. This is one of the most common false "internet is down" alarms: the ISP's DNS resolvers stop answering while its network is still up. Switch your router or device to a public resolver such as 1.1.1.1, 8.8.8.8 or 9.9.9.9, and confirm that names resolve with the DNS lookup. The DNS guide explains what resolvers do.
- Everything answers, but some sites fail. Your connection is up. The problem is those sites, a platform they depend on, or a routing issue between your ISP and them. Run
tracerton Windows ortracerouteon macOS and Linux to see where the path stops.
A simpler signal: if the IP address checker loads and shows your provider, your connection reaches the public internet, and whatever is failing sits further along the path.
Step 4: Check the Router's WAN Status
Your router's admin page shows exactly what it received from the ISP. Sign in using the router login guide and open the Internet, WAN or Status page. The WAN IP address field is the telling one:
- Blank or 0.0.0.0. The router did not get an address from the ISP. The modem is not online, the modem is not provisioned, or the ISP is not handing out addresses.
- 169.254.x.x. A self-assigned address. The router asked the ISP for an address and heard nothing back, which means the same as a blank field.
- 100.64.x.x to 100.127.x.x. This is the CGNAT range, normal on many mobile, satellite and fiber providers. It is not a fault on its own; it means the ISP shares public addresses between customers.
- Any other public address, but nothing loads.The ISP has connected you, yet something upstream, usually routing or DNS, is failing. That strongly suggests a problem on the provider's side.
Most routers also keep a system log. Repeated entries about failed DHCP renewals, PPPoE authentication errors, or the WAN link going up and down give support staff useful detail and speed up a fault report.
Step 5: Confirm With Your ISP and Outage Reports
Once the tests point past your router, confirm with outside sources. Use mobile data for this, and switch WiFi off on your phone so it stops trying the broken connection.
- Your ISP's app or status page.Major providers show outages tied to your service address once you sign in, often with an estimated repair time. This is the most reliable source because it comes from the provider's own monitoring. The ISP directory has profiles for providers such as AT&T, Xfinity, Spectrum, Verizon Fios and T-Mobile, including the network you should see when the connection works.
- Outage report websites. Sites that collect user reports show a spike when many people report the same provider at the same time. They usually flag an incident only when reports rise well above the normal level for that time of day, so a small local fault may never appear on the map.
- Social media and neighbors.Searching the provider name plus "down" on X or Reddit, or asking in a local community group, often confirms an outage before the provider does, and can reveal a physical cause such as a cut cable on your street.
- The support phone line. Automated phone systems usually announce known outages in your area before you reach an agent, which saves a long hold.
If two or more sources agree, stop troubleshooting. Restarting equipment again and again will not speed up a repair, and a factory reset can create new problems once service returns.
Is It Your ISP or the Whole Internet?
Sometimes your connection is fine and a large part of the web fails anyway. A handful of cloud, CDN and DNS providers sit behind thousands of websites and apps, so when one of them has a bad hour, unrelated services fail at the same moment and it feels as if the internet is down. The quick test is simple: if some sites load normally and others fail, your connection works, and the problem belongs to the services that are failing.
Backbone problems fall somewhere in between. The Cogent incident on September 2, 2026 started in Los Angeles and spread to other US cities and more than a dozen countries. Customers of ISPs that route through a failing carrier can reach some destinations but not others, which looks like a partial outage. Traceroute shows the pattern: the hops inside your ISP answer, then the path dies inside another carrier's network. For how these networks connect to each other, see What Is the Internet?
Common Causes of ISP Outages
- Fiber and cable cuts. Construction and digging crews damage buried cables more often than anything else. These outages tend to last longest, because crews must find the break and splice the cable before service returns.
- Power failures. Your modem needs power, and so do the street cabinets, nodes and exchanges that serve your neighborhood. Many have battery backup, but batteries run out during long power cuts.
- Weather. Storms bring down overhead cables, floods damage underground equipment and heat stresses outdoor cabinets. Satellite and fixed wireless connections also degrade in heavy rain or snow.
- Equipment failure. A single failed card in a node or exchange can cut off every customer connected to it.
- Planned maintenance. Upgrades usually happen overnight and are announced by email or in your account, so check there before calling support at 2 a.m.
- Routing and configuration errors.A bad software update or a routing (BGP) mistake can make an ISP's network unreachable even though every cable is intact. These are often fixed within minutes to hours once engineers roll the change back.
- DNS resolver failures.The network works, but the ISP's DNS servers stop answering, so names do not resolve. Step 3 shows how to spot this and work around it.
- DDoS attacks. Floods of traffic aimed at an ISP or one of its customers can overload shared links and slow or cut off everyone behind them.
When It Is Not an Outage
Some problems look exactly like an outage but come from the account, the equipment or the device itself:
- Account or billing holds. A suspended account often redirects every page to a payment portal, or blocks traffic completely.
- A new modem that is not activated. Cable ISPs register each modem by its hardware address, the MAC address explained in the network interface controller guide. A replacement modem stays offline until you activate it in the provider's app or through support.
- A data cap. Mobile, 5G home and satellite plans may slow to a crawl or stop once you hit your allowance.
- A VPN kill switch. A kill switch blocks all traffic whenever the VPN tunnel drops, and a stuck VPN client can do the same. Disconnect the VPN, and once pages load again, use the VPN checker to confirm the tunnel works when you reconnect.
- DNS settings or filters. A custom DNS server that has gone offline, a DNS filter, or a parental-control schedule can block browsing while the connection itself is fine.
- A wrong date and time. If your device clock is far off, HTTPS certificates look invalid and every secure site fails with a certificate error.
- Browser-only problems. If other apps work but the browser does not, check its proxy settings and extensions, or try a private window.
How to Fix Problems on Your Side
If your tests point to your own equipment, work through these in order. Each step is a little more disruptive than the last.
- Restart properly. Unplug both the modem and the router and wait 60 seconds. Plug in the modem first and wait until its Online or Internet light is solid, which can take a few minutes, then plug in the router.
- Check the cables. Reseat the power cable, the coax, fiber or phone line into the modem, and the Ethernet cable between the modem and the router. The Ethernet guide covers the signs of a damaged cable.
- Bypass the router. Connect a computer straight to the modem with an Ethernet cable. If that works, the router is the problem. Some cable modems remember the first device connected to them, so restart the modem after swapping devices.
- Reset the device's network settings. On Windows, run the commands below in an administrator Command Prompt, then restart. On macOS, open System Settings, Network, your connection, Details, TCP/IP, and choose Renew DHCP Lease.
ipconfig /release
ipconfig /renew
ipconfig /flushdns
netsh winsock reset- Try different DNS servers. Set 1.1.1.1 or 8.8.8.8 on the device or the router to rule out a DNS failure.
- Update the router firmware. Old firmware can have bugs that drop the WAN connection, especially after the ISP changes something on its side.
- Factory reset, as a last resort. A reset erases your WiFi names and passwords, port forwards and, on many DSL and fiber connections, the PPPoE username and password the router needs to log in to the ISP. Find those details first; they are usually in your welcome letter or account portal.
What to Do During a Confirmed ISP Outage
- Get an estimate.The ISP's app, text alerts or phone line usually give a repair estimate, and many providers text you when service is restored.
- Switch to mobile data.Share your phone's connection with a hotspot and keep an eye on data use: an hour of HD video can use several gigabytes, so lower streaming quality while you are on mobile data.
- Report it anyway.A logged fault on your account supports a credit request later, and it helps technicians find localized problems. A damaged cable serving only your street may not show up in the provider's network monitoring at all.
- Keep a record. Note when the outage started and ended, what the modem lights showed, and any reference numbers support gives you.
- Ask for a credit.Many ISPs credit your bill for outage time if you ask, and some do it automatically. In the UK, Ofcom's automatic compensation scheme requires participating providers to pay a set daily amount when a broadband fault is not fixed within two full working days.
- Escalate repeat outages. If the connection keeps dropping, ask for a technician visit and a line test. In the US, if that goes nowhere, file an informal complaint with the FCC, which forwards it to the provider for a response.
Build a Backup Plan Before the Next Outage
A few minutes of preparation turns the next outage from a crisis into an inconvenience, especially if you work from home:
- A phone plan with hotspot data. Check how much hotspot data your plan includes before you need it; some plans slow tethering after a small allowance.
- Automatic failover. Routers with a SIM slot or USB modem port switch to 4G or 5G when the main line fails, then switch back when it returns.
- A UPS for the modem and router.A small battery backup keeps your equipment running through short power cuts. It only helps if the ISP's equipment in your area still has power too.
- Your details offline. Keep your account number, support number, modem model and PPPoE login on paper or on your phone, not only in an email you cannot open during an outage.
- The provider's app, already signed in. Setting it up during an outage, over slow mobile data, is the worst time to reset a forgotten password.
- A second connection for critical work. A dual-WAN router with cable or fiber plus 5G home internet gives you two independent paths, so one cut cable cannot take you offline.
Is Your Internet Down or Just Slow?
A connection that is technically up can still feel down. Pages half load, video buffers and calls freeze. That is usually packet loss or latency spikes rather than an outage, and the fix is different.
Run a continuous ping to 1.1.1.1 for a minute while you use the connection normally (ping -t 1.1.1.1 on Windows, plain ping 1.1.1.1 on macOS and Linux). Occasional timeouts, or times jumping from 20 ms to several hundred, point to congestion, WiFi interference or a failing line. If it gets much worse while someone else uploads or streams, the cause is usually bufferbloat in the router, which the guide on how to reduce pingshows how to fix. Repeat the test over Ethernet to see whether WiFi is to blame. If the slowdown returns at the same time every evening, it may be congestion in the ISP's local network; record speed tests at different times of day before you contact support, because numbers get a faster response than descriptions.
Frequently Asked Questions
How do I know if my internet is down or just my WiFi?
Test another device on the same network and connect one device by Ethernet. If a wired device works while WiFi devices fail, the problem is your WiFi or router. If every device fails, wired included, the connection to your ISP is down.
How can I check if my ISP has an outage in my area?
Use mobile data, not your home WiFi, to open your provider's app or status page and sign in, since that shows outages tied to your address. Outage report sites and searches for your ISP name plus "down" show whether people nearby have the same problem.
Why does my modem say online but nothing loads?
The modem has a signal, but traffic still fails further along. Common causes are an ISP-side routing or DNS problem, a router that has not received a WAN address, or an account or provisioning issue. Ping 1.1.1.1: if it works but names do not resolve, switch DNS servers.
How long do internet outages usually last?
Most are short. Equipment restarts and routing faults are often fixed within minutes to a few hours; the AT&T outage on September 6, 2026 lasted 57 minutes. Physical damage such as a cut fiber or storm damage can take a day or more.
Can a VPN make it look like my internet is down?
Yes. A VPN with a kill switch blocks all traffic when the tunnel drops, and a stuck VPN client can do the same. Disconnect the VPN or pause the kill switch; if pages load again, the internet was never down.
Should I restart my router during an ISP outage?
One restart of the modem and router is harmless and clears local faults. Do not factory reset during a confirmed outage: it wipes your settings and, on DSL or fiber, your PPPoE login, which you will need once service returns.
Can I get money back for an internet outage?
Many ISPs credit your bill for an outage if you ask, and some do it automatically. Note the start and end times and contact support. In the UK, Ofcom's automatic compensation scheme pays a set daily amount if a broadband fault is not fixed within two full working days.
Related reading: What Is My ISP?, WiFi guide, Router login guide, Understanding DNS and Fiber optic internet.
