If you're reading this, one useful fact is already established: this page loaded. Either your internet works and something narrower is broken, or — more likely — you're on mobile data because your home connection is out. That distinction is the whole diagnosis, so let's use it properly.
First, be honest about what a website check can tell you ¶
Checking xfinity.com from our network tells you whether Xfinity's website answers — from our servers, over our route. It does not measure the coax cable in your street or the fiber node serving your block. An ISP's access network and its website are different systems: the website can be up while your neighborhood is dark, and during a big regional outage the website sometimes buckles under the login stampede while most customers' connections are fine.
So a remote check is one honest signal, not a verdict: if an ISP's own site and portal stop answering our probes, that's often smoke from a real fire. If they answer fine, your outage — if you have one — is local or regional, and the steps below will find it.
The 2-minute diagnosis ¶
- Switch to mobile data (turn Wi-Fi off on your phone). If pages load on cellular but not on Wi-Fi, the problem is between your router and your ISP — not "the internet".
- Look at the modem lights. A steady "Online" light with no internet points at the router or DNS. A blinking or dead "Online"/"DS/US" light means the modem can't reach the ISP — that's an access-network problem, theirs or your line's.
- Check the ISP's own status, over cellular. Every major US provider has an app or outage page that knows YOUR address: Xfinity's app shows outages on your account; Cox, Spectrum, and AT&T do the same. This is the only source that can see your street. Our checks — Xfinity, Cox, Spectrum, AT&T — tell you whether their public sites are up at all.
- Power-cycle the modem and router — 30 seconds off, modem first, router after it settles. This clears a stuck DHCP/DNS state, which is the most common "outage" that was never an outage.
Symptom → what's actually wrong ¶
| What you see | Likely cause | What to do |
|---|---|---|
| Nothing loads; modem "Online" light out or blinking | ISP access network (their side of the wall) | Check the ISP app over cellular; report it; wait — restarts won't fix their node. |
| Nothing loads; modem lights normal | Router, Wi-Fi, or DNS in your house | Power-cycle; try a wired connection; flush DNS. |
| Some sites load, others don't | DNS or a single site's outage — not your ISP | Check the failing site itself; see NXDOMAIN if it's DNS errors. |
| Internet works, but slow every evening | Congestion, not an outage | Different problem entirely — an outage check will always say "up". |
| Whole neighborhood down (neighbors confirm) | Regional ISP outage | Their status app is the authority; ours shows whether their site is also struggling. |
Why "is Xfinity down" is usually the wrong question ¶
Nation-scale ISP outages are rare. What's common is a node outage covering a few thousand homes, a cut line covering a street, or a dead router covering exactly one house. That's why the mobile-data test comes first: it instantly tells you which radius you're in. A whole-ISP verdict — ours or anyone's — can't see any of those radii. Anyone who claims a single remote probe can tell you "Xfinity is down for you" is selling certainty they don't have.
FAQ ¶
Is Xfinity down or is it just me?
Turn off Wi-Fi on your phone. If cellular works and your home connection doesn't, check your modem lights: dead "Online" light → their network, report it via the app. Normal lights → your router or DNS, power-cycle first. Our xfinity.com check adds one more signal: whether their public site is answering at all.
Why does the outage map say I'm fine when my internet is out?
Outage maps aggregate reports and node telemetry; a cut drop line to one house shows nothing. If cellular works, the modem can't sync, and the map is green, call it in — you may be the first report on your street.
My internet is up but one site won't load — is my ISP blocking it?
Almost never. Check the site itself first — it's usually the site. If many sites fail with DNS errors, switch DNS servers before blaming the ISP.