Can an iPhone really make a WiFi heatmap?
Yes. A WiFi heatmap is just many signal-strength measurements pinned to positions on a floor plan, then interpolated into a colour gradient. Your iPhone reads the signal strength of the network it's connected to in real time, so all a heatmap app has to do is let you tell it where each reading was taken. No external antennas, laptops, or enterprise survey kits required.
What you get at the end is a map where every room is coloured by signal quality — strong areas, weak areas, and true dead zones become visible at a glance. If you've been debugging WiFi by walking around watching the bars, a heatmap replaces that guesswork with data.
How to create a WiFi heatmap on iPhone with HeatFi
HeatFi (WiFi Heatmap Planner) is a free iOS app built for exactly this. The whole survey takes about 10 minutes for a typical home:
- Add your floor plan. Draw it freehand in the app, import an image of a blueprint, or snap a photo of a printed plan. HeatFi scales it automatically.
- Walk and sample. Move through each room, stand where you actually use WiFi (sofa, desk, bed) and tap Take Sample. The app pins the live signal reading to your position on the plan.
- Generate the heatmap. HeatFi interpolates your samples into a full-coverage map with per-room signal scores, and you can export it as PDF or PNG.
What to do with your heatmap
The map usually points to one of three fixes:
- Move the router. If strong coverage is bunched in one corner of the map, your router is badly placed. See our router placement guide.
- Add a node or extender. If one wing or floor is weak, place a mesh node or extender at the edge of the strong zone — the heatmap shows you exactly where that edge is. See where to put a WiFi extender.
- Change bands. If close rooms are fast but distant rooms collapse, you may be on 5 GHz only — read 2.4 vs 5 vs 6 GHz.
Then re-run the survey after the change. A before/after heatmap is the only reliable proof a fix actually worked.
Quick answers
Does iPhone have a built-in WiFi heatmap tool?
No. iOS shows signal bars for the connected network but has no built-in way to map signal across a floor plan. You need a heatmap app like HeatFi, which is free on the App Store.
Is a WiFi heatmap app on iPhone accurate?
Accurate enough to find dead zones and compare before/after changes. Phone measurements are within a couple of dB of dedicated hardware, and since your phone is the device you actually use, its readings reflect your real experience.
Do I need to buy anything to make a WiFi heatmap?
No. HeatFi is free, works offline, requires no account, and uses only your iPhone's own WiFi readings.
See your WiFi instead of guessing
HeatFi turns your phone into a WiFi survey tool. Draw your floor plan, walk each room, and get a colour-coded heatmap in minutes. Free — no account needed.
