The quality of a wireless connection directly impacts the comfort of internet use, whether it's online gaming, watching 4K video, or video conferencing. Users often encounter situations where the indicators on their smartphone screen show a full connection, but pages load slowly or videos constantly buffer. This occurs because the graphical display of signal strength often doesn't reflect the actual bandwidth.
Understanding that, How to check the signal strength of a Wi-Fi router Digitally expressed, it allows you to accurately diagnose network problems. Instead of guessing, you receive precise decibel readings, allowing you to objectively assess the coverage quality in different rooms. This is the first and most important step before purchasing expensive network expansion equipment.
In this article, we'll explore professional and affordable methods for measuring reception strength on various devices. You'll learn how to interpret the resulting values, distinguish real interference from software errors, and understand when it's truly necessary to adjust your equipment settings or rearrange your furniture.
Why is the "sticks" indicator on the screen lying?
Visually displaying signal strength as arcs or dots on a smartphone or tablet screen is extremely simplistic. Operating systems hide precise technical data from the user, providing only an approximate estimate. The problem is that different gadget manufacturers calibrate their scales differently.
Android And iOS They can show 3 or 4 bars even with a fairly weak signal, which is incapable of providing a stable, high speed. Furthermore, the number of bars doesn't take into account the level of noise and interference in the airwaves. The signal may be strong, but "dirty" due to neighboring routers, and the speed will still be low.
⚠️ Attention: Don't rely solely on the operating system's graphical indicators when diagnosing internet problems. They are designed for quick network availability assessments, not for precise network engineering tuning.
To get an objective picture, it's necessary to refer to numerical power values measured in dBm (decibel milliwatts). This parameter represents the actual physical strength of the radio wave reaching your device's receiver. Understanding this metric allows you to compare coverage at different points in your apartment with mathematical precision.
Units of measurement and decoding of dBm values
The basic unit of signal strength is dBm. This is a logarithmic unit that expresses the ratio of signal strength to 1 milliwatt. A unique feature of this scale is that the values are always negative. The closer the value is to zero, the stronger the signal.
For example, -40 dBm represents an excellent signal, while -90 dBm means virtually no connection. The difference between these values only seems small at first glance, but on a logarithmic scale, each 3 dBm step doubles or halves the signal strength.
Why are the values negative?
The signal power is always less than 1 milliwatt (the reference value), so the logarithm of the ratio is negative. In radio wave physics, this is the norm, and the smaller the negative, the better the connection.
Below is a table to help you interpret the values you receive from your measurements:
| Value (dBm) | Signal level | Job Description |
|---|---|---|
| -30.. -50 | Great | Maximum speed, ideal for 4K and gaming |
| -51.. -65 | Good | Stable operation, suitable for streaming |
| -66.. -75 | Average | Speed drops are possible, web surfing is normal |
| -76.. -85 | Weak | Unstable connection, possible interruptions |
| -86.. -100 | Critical | There is a connection, but there is practically no data. |
Using this data, you can walk around your apartment and record readings at different points. If you have -55 dBm in one room and -80 dBm in the next, it means a wall or obstacle is critically attenuating the signal. This information will help you correctly place your router or choose a location for a repeater.
Checking signal strength on Windows and macOS
Personal computer operating systems provide more detailed information than mobile devices, although standard tools still often hide precise dBm values. However, there are proven ways to obtain this data without installing third-party software.
In the environment Windows You can use the command line to get basic information about connection quality. Open the command line (cmd) and enter the command netsh wlan show interfacesIn the list that appears, find the "Signal" line, where the quality will be indicated as a percentage.
netsh wlan show interfacesWhile percentages are easier to understand, they are less accurate than dBm. For professional data on Windows, it's better to use specialized utilities such as Acrylic Wi-Fi Home or WiFi Analyzer from the Microsoft Store. These programs plot signal attenuation graphs in real time.
For users macOS You're luckier: the system has a built-in hidden diagnostic tool. Hold down the key Option (Alt) on your keyboard and simultaneously click the Wi-Fi icon in the top menu bar. A line will appear in the drop-down list. RSI (Received Signal Strength Indicator), where the exact value in dBm will be indicated.
You can also launch the Wireless Network Manager in macOS via Spotlight search by typing /System/Applications/Utilities/Wi-Fi Diagnostics.appIn the program window, select "Monitoring" to view a graph of signal fluctuations and noise levels in real time.
Diagnostics on Android and iOS: Built-in Methods
Mobile devices are the most frequent clients of a home network, so signal testing on them is especially important. However, mobile OS manufacturers restrict access to the radio module hardware in every possible way, hiding exact signal strength from the average user.
On devices with the operating system Android The situation depends on the OS version and the manufacturer's shell. In some cases, you can use the hidden engineering menu. To do this, enter the code in the "Phone" app. ##4636##If a menu opens, select "Wi-Fi Information" where the current signal strength (RSSI) will be displayed in dBm.
⚠️ Attention: Engineering menu codes may vary depending on the smartphone model (Samsung, Xiaomi, Huawei). If the code doesn't work, use third-party apps from Google Play, as they utilize standard system APIs.
For users iPhone (iOS) accessing this data is more difficult due to the closed nature of the system. There are no standard ways to view dBm in the interface. The only legal way is to use an app. Apple Support (the official Apple app). Select your device, go to the "Wi-Fi Info" section, and find the RSSI parameter.
An alternative option for iOS is to use the logger mode, but this requires connecting to a macOS computer and installing Xcode, which is too complex for a quick check. Therefore, for iPhone, the most practical solution remains installing third-party Wi-Fi analyzers, which at least visualize signal strength in more detail than the standard "shutter."
Professional tools and third-party applications
If built-in tools aren't enough, specialized apps can help. They not only display current signal strength but also help analyze channel load, which is critical in multi-apartment buildings.
The most popular and effective applications for analysis:
- 📡 WiFi Analyzer (Open Source) — a completely free Android app without unnecessary fluff, showing graphs of the power of all networks.
- 📶 NetSpot — a professional tool for Windows and macOS that allows you to create heat maps of coverage (requires a walk-through of the premises).
- 📱 Fing — a popular app for iOS and Android that scans the network, shows signal quality, and identifies connected devices.
- 💻 Acrylic Wi-Fi Home — a powerful analyzer for Windows with detailed graphs and the ability to export logs.
Using such programs allows you to see not only your signal strength but also understand how much interference your neighbors are causing. If your network is -60 dBm, and your neighbor's is screaming at -55 dBm on the same channel, your speed will be low due to collisions, even if the reception level is good.
To conduct a professional measurement (audit), it's recommended to create a spreadsheet in a notebook and go through each room, recording RSSI values. This will help you identify "dead zones" where the signal drops below -80 dBm and determine whether additional equipment is needed.
Factors Affecting Signal Strength and Ways to Improve It
Knowing how to measure a signal, it's important to understand what exactly attenuates it. Radio waves in the 2.4 GHz and 5 GHz bands behave differently in space. Higher frequencies (5 GHz) attenuate faster when passing through obstacles but provide higher speeds. Low frequencies (2.4 GHz) bypass obstacles better but are more susceptible to interference.
The main enemies of Wi-Fi signal in an apartment:
- 🧱 Thick walls and concrete — the reinforcement inside the walls acts as a Faraday cage, blocking radio waves.
- 🪞 Mirrors and metal surfaces - reflect the signal, creating interference zones.
- 📺 Household appliances - Microwave ovens and baby monitors operate in the 2.4 GHz range, creating powerful noise.
- 📦 Router location — a device hidden in a niche or behind a TV loses up to 50% of its efficiency.
☑️ Checklist for signal improvement
⚠️ Attention: Router settings interfaces and app functionality are constantly being updated. The layout of menu items may vary depending on your device's firmware version. Please check the router manufacturer's website for the latest instructions.
To improve the situation, simply moving the router to the center of the apartment or raising it 1.5–2 meters is often sufficient. The antennas should be pointed vertically. If these measures don't help, and measurements show critically low values, it's worth considering a mesh system that creates a single, seamless network, or a repeater to expand the coverage area.
Frequently Asked Questions (FAQ)
What signal level in dBm is considered normal for gaming?
For online games, where not only speed but also stability (low ping) is important, a signal level of at least -65 dBmAt values below -70 dBm, lags and packet losses may be observed, even if the download speed is formally high.
Why does Wi-Fi speed drop even though the signal is full?
A full signal (for example, -40 dBm) only indicates the radio wave's strength, not its "purity." Speed can drop due to high channel congestion from neighbors, interference from Bluetooth devices or microwave ovens, as well as limitations of the router itself or the provider's plan.
Does the number of connected devices affect signal strength?
No, the number of devices does not affect the physical signal strength (the router's radiated power). However, each new device consumes some of the router's bandwidth and CPU time, which may result in a perceived "slow" internet speed, even though the reception level (RSSI) remains the same.
Can foil or a can boost Wi-Fi signal?
Theoretically, a directional foil reflector can focus the signal in one direction, amplifying it there but weakening it in other directions. In practice, homemade designs often create interference and worsen the situation. It's better to properly adjust the antennas or purchase a certified amplifier.
How often should I check my Wi-Fi signal?
A thorough measurement is sufficient once during network setup or if connection issues arise. Unless you've changed your apartment's layout, purchased new powerful appliances, or upgraded your router, indoor radio wave propagation parameters will remain stable.