Slow internet at the most inopportune moments is a familiar problem for every wireless network owner. You try to watch a high-definition movie, but the image turns into pixels, or a video call turns into a slideshow. Users often blame their internet service provider, when the real cause lies in the operation of their home router or interference in the air.
Before calling technical support, it's important to conduct an objective measurement of your connection parameters. This will help you distinguish between issues with your service provider and local hardware problems. Proper diagnostics are the first step to ensuring a stable home network.
Understanding Metrics: Bits, Bytes, and Ping
First, it's important to understand the units of measurement to correctly interpret test results. Internet speed is typically measured in megabits per second (Mbps).Mbps or Mbit/s), while the size of files on a hard drive is indicated in megabytes (MB). Confusion between these concepts often leads to false conclusions about the provider's poor performance.
The second critical parameter is ping, or latency. It measures the time it takes for a data packet to reach the server and return. For online gaming and video calls, a low ping is more important than maximum download speed. A high ping causes lag, even if files are downloading quickly.
Channel asymmetry should also be considered. On most residential plans, download speeds are significantly higher than upload speeds. This is fine for content consumption, but can create problems when sending large files or streaming.
⚠️ Important: When testing, make sure that no other devices on the network are downloading updates or torrents, otherwise the measurement results will be distorted.
Why is WiFi speed always slower than wired speed?
Wireless signals are subject to attenuation, reflection from walls, and interference from neighboring networks. Even under ideal conditions, losses range from 20% to 40% of the speed achieved via cable.
Online services for quick verification
The easiest way to get instant results is to use specialized websites. They automatically select the closest server and run a series of tests, producing final results. The most popular tool remains Ookla Speedtest, which has a huge database of servers all over the world.
Other services such as Fast.com from Netflix or Yandex.Internetometer, also show good results. They may use different compression and routing algorithms, so to get a complete picture, it's recommended to run the test on two or three different services and calculate the average.
When using browser tests, it's important to disable ad-blocking or script-blocking extensions, as they can interfere with data transfer. It's also a good idea to close any unnecessary tabs that consume bandwidth to ensure the integrity of the experiment.
Using the Command Line for Pros
For a more in-depth network analysis, you can use the operating system's built-in tools. The command line allows you to check not only the response speed but also the stability of the connection over time. This is especially useful for diagnosing intermittent issues, when the internet connection "drops out" periodically.
On Windows and Linux/macOS the main command is pingIt sends small data packets to a specified address and measures the response time. By running the command with the continuous polling flag, you can monitor network behavior in real time.
To run the test in Windows, click Win + R, enter cmd and press Enter. In the window that opens, enter the command:
ping 8.8.8.8 -tHere 8.8.8.8 — is Google's highly available DNS server. Flag -t forces the system to send requests endlessly until you stop the process yourself with a keyboard shortcut Ctrl + C. Pay attention to the parameter time (time) and the presence of lines Request timed out, which indicate packet loss.
Speed test on different devices
Test results can vary dramatically depending on the device you're using. An older smartphone with a standard Wi-Fi module 802.11n physically will not be able to show high speed, even if the router supports the latest standard WiFi 6 (802.11ax).
Computers with external USB adapters often perform worse than laptops with built-in antennas. The operating system and background processes also play a role: antivirus software or cloud synchronization services can consume some of the bandwidth during the test.
To get objective data, take measurements on several devices:
- 📱 Smartphone (last 2-3 years of production)
- 💻 Laptop with built-in WiFi
- 🖥️ Desktop PC (if you have a WiFi adapter)
- 📺 Smart TV (via built-in apps or browser)
If the speed is normal on one device, but slow on another, the problem lies in the characteristics of the specific device or its drivers, and not in the operation of the router.
Factors Affecting Signal Quality
Wireless connections are extremely sensitive to physical obstacles and electromagnetic interference. Microwave ovens, Bluetooth headphones, and even aquariums can significantly reduce channel throughput. Router placement plays a key role in determining coverage.
It's important to distinguish between the 2.4 GHz and 5 GHz frequency bands. The former offers better penetration but is heavily congested by neighboring networks. The latter offers higher speeds but is less effective at penetrating walls. Switching between them can instantly change test results.
The main sources of interference and speed reduction are:
- 🧱 Thick concrete walls and metal reinforcement
- 📡 Mirrors and tinted glass
- 🔌 Working household appliances (refrigerators, microwaves)
- 📶 Neighboring routers on the same channel
☑️ Interference diagnostics
Comparison of wired and wireless connections
To understand how effective your WiFi is, compare its performance to a wired connection. An Ethernet cable (twisted pair) ensures stable data transmission without loss to radio waves and virtually eliminates external interference.
Connect your laptop or PC directly to the router using a patch cord and repeat the speed test. The difference between the resulting figures and the WiFi results will indicate the actual wireless interface loss. Under ideal conditions, losses should not exceed 20-30%.
Comparison table of connection characteristics:
| Parameter | WiFi (5 GHz) | WiFi (2.4 GHz) | C Ethernet (Cat 5e) |
|---|---|---|---|
| Max. speed (theoret.) | up to 866 Mbps | up to 150 Mbit/s | 1000 Mbps |
| Ping stability | Average | Low | High |
| The influence of walls | Strong | Average | Absent |
| Vulnerability to interference | Average | High | Low |
If the speed via cable matches the plan, but via WiFi it's significantly lower, then you need to optimize your router settings or change its location.
Frequently asked questions and answers
Why does WiFi speed drop in the evening?
In the evening (7:00 PM to 11:00 PM), there is a peak load on provider networks. Furthermore, neighbors actively use the internet, which creates congestion, especially in the 2.4 GHz frequency.
Does the number of connected devices affect the speed?
Yes, the router distributes the channel's bandwidth among all active clients. If one user is downloading games, the others will have fewer resources. Modern routers with this feature QoS can prioritize traffic.
Do I need to reboot my router before testing?
Rebooting helps clear the device's RAM and clear any software errors accumulated during uptime. For the most accurate results, it is recommended to reboot the router 5 minutes before starting measurements.
How to check the speed on a TV?
On Smart TV you can install applications like Speedtest by Ookla from the app store. If installation is not possible, play a 4K video on YouTube and observe the image quality, or use the built-in browser to access the test website.