How to make a WiFi heatmap on iPhone (and find your dead zones)
By Rupangkan KalitaPublished
Install WiFi Heatmap & Coverage Map on an iPhone 12 Pro or later (or a LiDAR iPad). Point it at the walls and walk through each room: the floor plan draws itself and your WiFi is painted across it, green where it works and red where it dies. The app then marks the dead spot and where a booster would help.
A WiFi heatmap shows how well your WiFi works in every part of your home, coloured green where it is strong and red where it dies. On a LiDAR iPhone you can make one yourself in about ten minutes, with no floor plan to draw and no extra hardware.
What does a WiFi heatmap tell you that a speed test doesn't?
A speed test answers one question in one spot. A heatmap answers it everywhere you walk, so you can see that the bedroom behind the bathroom wall is the problem, and not the router or the laptop. You know where to put the fix instead of guessing.
What do you need?
- An iPhone 12 Pro or later, or an iPad with LiDAR (iOS 17 or later).
- Your home WiFi, connected as usual.
- About ten minutes.
How do you make the heatmap, step by step?
- Scan. Open WiFi Heatmap & Coverage Map, point your iPhone at the walls and walk through each room. The floor plan builds as you go.
- Walk. Keep walking around each room. Every square of the floor lights up as you cover it, so you can see when a room is done.
- See. Your rooms appear in 3D with the signal laid on the floor: green where it works, red where it dies. The exact spot where it gives up is marked.
- Fix. The app shows where a booster or mesh node would go, and how much of the dead space it would rescue.
What is being measured if not dBm?
iOS does not let any app read WiFi signal strength, so an app showing a decibel figure is estimating it. WiFi Heatmap records four things it can genuinely measure at the spot you are standing: round-trip time to your own router, how much that varies (jitter), packet loss, and real throughput. Together they decide whether a video call survives in that room. You can also tell the app what speed you pay for, and it compares your speed readings with that plan.
How do you read the map?
- Green: strong. WiFi holds up here.
- Amber: in between: usable, but weaker than green.
- Red: the dead zone. This is where the fix goes.
If one room is red and the next is green, look at what sits between them: a bathroom, a staircase, a thick wall or a fridge often explains it.
What should you do with the result?
- Move the router to a more central, open spot if the red patches are all on one side of the home.
- Add a booster or mesh node where the app suggests, so it sits in strong signal and still reaches the dead zone. Both halves matter.
- Hand the report to your landlord or provider if the problem is theirs to fix.
Comparing tools first? See how it stacks up as a NetSpot alternative for iPhone, or get WiFi Heatmap & Coverage Map on the App Store.
Questions
What is a WiFi heatmap?+
A map of your space coloured by how well WiFi works in each spot, usually green for strong and red for weak. It shows where the dead zones are, which a single speed test in one room cannot.
Can I make a WiFi heatmap with just my iPhone?+
Yes. WiFi Heatmap & Coverage Map uses the LiDAR scanner on iPhone 12 Pro and later (and LiDAR iPads) to draw your rooms, then records your WiFi as you walk. No extra hardware and no floor plan to import.
How long does a home WiFi heatmap take?+
About ten minutes for a typical home: scan each room, walk through it, and the map fills in as you cover the floor.
Does the heatmap show signal strength in dBm?+
No iPhone app can read the WiFi signal level, because iOS does not offer it to third-party apps. WiFi Heatmap records round-trip time to your router, jitter, packet loss and throughput at each spot instead.
What do I do once I find a dead zone?+
WiFi Heatmap marks the spot where the signal gives up and shows where a booster or mesh node would go, plus how much of the dead space it would rescue. Moving the router or adding a node at that spot is usually the fix.
Does my iPhone need LiDAR?+
To scan rooms, yes: iPhone 12 Pro or later, or a LiDAR iPad. Support for other iPhones is on the app's roadmap.
Is my home scan uploaded anywhere?+
No. There is no account, and every scan and reading stays on your device.
Sources
- WiFi Heatmap & Coverage Map on the App Store (checked 2026-11-02)