How to Measure WiFi Signal Strength with WiFiman: A Deep Dive into Home Network Mapping

If you've ever wondered why your WiFi is fast in one room and painfully slow in another, you need a way to actually measure what's happening. Enter WiFiman — a free app from Ubiquiti that turns your phone into a powerful WiFi analyzer.

I've been using WiFiman on iOS to map my home network, identify dead zones, and optimize my mesh node placements. It's one of those tools that makes you realize how much you've been guessing about your WiFi coverage. In this guide, I'll walk you through everything WiFiman can do and how to use it effectively.

What is WiFiman?

WiFiman is a free network analysis app developed by Ubiquiti (the company behind UniFi networking gear). While it's made by Ubiquiti, you don't need any Ubiquiti hardware to use it — it works with any WiFi network.

Available on both iOS and Android, WiFiman offers:

• Real-time WiFi signal strength measurements (RSSI)
• Speed tests (download, upload, latency)
• Network scanner to discover all devices
• WiFi channel analysis and interference detection
• Home mapping with signal heatmaps

Best of all? It's completely free with no ads.

Understanding WiFi Signal Strength (RSSI)

Before we dive into the app, let's talk about what we're measuring. WiFi signal strength is expressed in RSSI (Received Signal Strength Indicator), measured in dBm (decibels relative to one milliwatt).

Here's the key thing to understand: RSSI values are negative numbers, and closer to zero is better.

RSSI Signal Strength Guide

• -30 to -50 dBm: Excellent — You're very close to the access point. Maximum speeds possible.
• -50 to -60 dBm: Very Good — Strong signal. Reliable for all activities including 4K streaming and video calls.
• -60 to -70 dBm: Good — Adequate for most uses. Web browsing, HD streaming, and general use will work fine.
• -70 to -80 dBm: Weak — Minimum for reliable connectivity. You may experience buffering and slower speeds.
• -80 to -90 dBm: Very Weak — Unreliable connection. Frequent dropouts likely.
• Below -90 dBm: Unusable — Connection will drop constantly or not work at all.

For mesh networks, aim for at least -65 dBm coverage throughout your home. For demanding applications like gaming or video conferencing, target -60 dBm or better.

Getting Started with WiFiman

Step 1: Download the App

Download WiFiman from the App Store (iOS) or Google Play Store (Android). It's free and takes up minimal storage.

Step 2: Grant Permissions

The app needs location permission to access WiFi information (this is an OS requirement, not data collection). On iOS, you'll also need to enable Local Network Access for device scanning.

Step 3: Connect to Your WiFi

Make sure you're connected to the WiFi network you want to analyze. WiFiman will automatically detect and display your current connection.

WiFiman Features Deep Dive

1. Real-Time Signal Strength

The main screen shows your current connection with a live RSSI reading. This updates in real-time, so you can walk around your home and watch the signal strength change.

What to look for:

• RSSI value (the dBm number)
• Which band you're connected to (2.4 GHz vs 5 GHz vs 6 GHz)
• Channel number
• Link speed (PHY rate)

2. Speed Test

WiFiman includes a built-in speed test that measures:

• Download speed — How fast you can pull data from the internet
• Upload speed — How fast you can send data
• Latency (ping) — Response time in milliseconds
• Jitter — Variation in latency (important for video calls and gaming)

Pro tip: Run speed tests in different rooms to see how location affects your actual throughput, not just signal strength.

3. Network Scanner

The network scanner discovers all devices on your local network. This is useful for:

• Seeing how many devices are connected
• Identifying unknown devices (security check)
• Finding IP addresses of devices
• Checking if smart home devices are online

4. WiFi Scanner (Channel Analysis)

This feature scans for all nearby WiFi networks and shows:

• All visible networks and their signal strength
• Which channels are congested
• Channel overlap visualization
• Security protocols in use (WPA2, WPA3, etc.)

Note: On iOS, WiFi scanning capabilities are limited compared to Android due to Apple's restrictions. You'll see your connected network but may not see all nearby networks.

Home Mapping: The Killer Feature

This is where WiFiman really shines. The Survey feature lets you create a visual heatmap of your WiFi coverage.

How to Create a WiFi Heatmap

1. Tap the Survey tab in the app
2. Create a new survey and give it a name (e.g., "Main Floor")
3. Add a floor plan — You can take a photo, upload an image, or use the built-in drawing tool to sketch your layout
4. Set the scale by marking a known distance (like a wall length)
5. Walk to each area and tap to record — Stand in a spot, tap on that location on your floor plan, and the app records the signal strength
6. Repeat throughout your home — More sample points = more accurate heatmap
7. View the heatmap — Green = strong signal, yellow = moderate, red = weak

Tip: Take readings in corners, near walls, and in spots where you actually use WiFi (desk, couch, bed). The more data points, the better your heatmap.

Using WiFiman to Optimize Mesh Node Placement

If you have a mesh WiFi system (like Eero, Google Nest WiFi, or Ubiquiti), WiFiman is invaluable for finding the optimal node placement.

The Process

1. Create a baseline heatmap with your current setup
2. Identify dead zones (red/orange areas on the heatmap)
3. Move a mesh node to a new location
4. Create a new heatmap and compare
5. Repeat until you have consistent coverage

Mesh Node Placement Tips

• Nodes should "see" each other — Place nodes where they maintain at least -65 dBm signal to the main router
• Avoid placing nodes too far apart — They need good backhaul signal to perform well
• Elevate nodes — WiFi radiates outward and downward. Placing nodes on shelves or desks (not on the floor) improves coverage
• Avoid obstacles — Metal objects, aquariums, mirrors, and thick walls significantly weaken signals
• Keep away from interference — Microwaves, baby monitors, and cordless phones can interfere with 2.4 GHz

Understanding 2.4 GHz vs 5 GHz vs 6 GHz

WiFiman shows which band you're connected to. Here's what each offers:

2.4 GHz

• Better range and wall penetration
• Slower speeds (typically max ~150-300 Mbps)
• More congested (many devices use this band)
• Good for: IoT devices, smart home gadgets, devices far from router

5 GHz

• Faster speeds (up to 1+ Gbps)
• Shorter range, worse wall penetration
• Less congested, more available channels
• Good for: Streaming, gaming, video calls, laptops, phones

6 GHz (WiFi 6E/7)

• Fastest speeds available
• Shortest range
• Virtually no congestion (new spectrum)
• Requires WiFi 6E or WiFi 7 compatible devices

Pro Tips for Accurate Measurements

• Hold your phone consistently — Don't cover the antenna area (usually at the top or bottom of the phone)
• Take multiple readings — WiFi signals fluctuate. Take 2-3 readings per location
• Test at different times — Interference can vary throughout the day, especially in apartments
• Test at usage height — Hold your phone at desk/table height, not over your head
• Disable VPN — VPNs can affect speed test results

Related Reading

Pro tip: If your mesh nodes are too far apart for reliable wireless backhaul, consider using MoCA adapters to create a wired backbone over your existing coax cables. I wrote about this in my MoCA adapters guide — it's a game-changer for multi-story homes.

Good WiFi coverage is especially important if you have smart home devices scattered throughout your house. Check out my smart home setup to see how I've built out my connected home.

If you're planning a smart home, understanding WiFi bands matters because different protocols use different frequencies. Thread devices, for example, create their own mesh network. Learn more in my Matter and Thread explainer.

Final Thoughts

WiFiman has become one of my go-to tools for home networking. It takes the guesswork out of WiFi troubleshooting and gives you actual data to work with.

The heatmap feature alone is worth the download. Being able to visualize exactly where your coverage is weak makes mesh node placement so much easier. Instead of randomly moving nodes and hoping for the best, you can make informed decisions based on real measurements.

Best of all, it's completely free. No ads, no premium tier, no data collection. Just a solid, well-designed tool from Ubiquiti.

If you're struggling with WiFi dead zones or just want to optimize your mesh network, give WiFiman a try. You might be surprised by what you discover about your home's WiFi coverage.