No single map tells you whether a phone will work in your kitchen. What exists is a set of sources that each answer part of the question, from a whole state down to one address, and the trick is to use them in order. This is that order.
Nationally, 69.8% of US area has 4G LTE from at least one of AT&T, T-Mobile or Verizon on filings to the FCC as of December 31, 2025. The share where all three cover you is lower, and the share where your building lets the signal in is lower still.
Step 1: your ZIP code, city or state on NetScanAI
Type your ZIP code into the checker on our homepage. It resolves the ZIP to the Census place or county it sits in and shows the share of that area where each of AT&T, T-Mobile and Verizon reports 4G LTE or 5G, outdoors and in a moving car, from the carriers' own FCC filings. It names a leader only when one carrier is clearly ahead once the area's water is allowed for.
The state pages and city pages give the same figures for the wider area, which matters if you commute or travel. A ZIP with no FCC row gets a no-data page, never an estimate.
Step 2: the exact address on the FCC map
Our figures stop at the city or county. For one address, open the FCC National Broadband Map, search the address, and switch to the mobile view. It shows, for each carrier, whether that carrier has filed 4G LTE or 5G coverage at that point, outdoors and in a vehicle, on the same filing our figures come from. It is the only place every carrier's map appears in the same format.
Step 3: the carrier's own map
AT&T, T-Mobile and Verizon each publish a coverage map. They are more detailed than the FCC map and often distinguish 5G types, but each is drawn by the carrier in its own way, so they cannot be compared with each other. Use them to check the one carrier you are leaning towards, not to rank the three.
| Source | Covers | What it tells you | |
|---|---|---|---|
| NetScanAI ZIP checker | ZIP code, city or county | All three carriers side by side, outdoors and in a car, with a leader only where the FCC figures justify one | View → |
| NetScanAI state pages | State, with its largest cities | Each carrier's share of the state, plus the all-carrier 5G share | View → |
| FCC National Broadband Map | A single address | Whether each carrier has filed 4G LTE or 5G there, outdoors and in a vehicle | Visit → |
| AT&T coverage map | A single address | AT&T's own map, in its own format | Visit → |
| T-Mobile coverage map | A single address | T-Mobile's own map, in its own format | Visit → |
| Verizon coverage map | A single address | Verizon's own map, in its own format | Visit → |
| How to read the FCC map | Background | What the FCC's outdoor, in-vehicle and 5G tiers mean | View → |
Carrier maps open on the carrier's site.
What "carrier-reported" means
Every figure on this site, and everything on the FCC map, is what the carrier itself filed: a map of where it says a phone gets at least 5 Mbps down and 1 Mbps up on 4G LTE, or 7/1 and 35/3 Mbps on 5G. Nobody drove the roads to check. The FCC lets the public challenge a carrier's map with speed tests, but until a challenge succeeds, the map stands as filed.
Treat it as each carrier's best case. A carrier will rarely under-report; it can over-report, and the FCC map cannot see indoors.
Why the area percentage includes water
The FCC's area for a city, county or state includes its lakes, rivers and coastal water. New York City is over a third water. Some carriers file coverage across the water, some stop at the shore, so two carriers covering the same land can show very different percentages. That is why NetScanAI names a leader only when the gap between carriers is larger than the water share, and shows a range otherwise. A carrier ahead by less than the water share may simply have drawn its map over the bay.
Before you switch
Signal indoors is not in any filing. Walls, glass and the floor you live on decide it, and the only test is a phone on that network inside your home. Ask the carrier whether it offers a trial or a short return window, and if you can, borrow a phone on that network from a neighbor for an evening.
Check the places you actually go, not only home: work, the school run, the route you drive. The in-car figure on our state and city pages is the one for the drive. And keep your number: US carriers must let you port it when you leave.