How to Measure Internet Speed: A Complete Testing Guide

In today's digital world, diagnosing internet speed has become a common necessity. Complex network infrastructures, bandwidth congestion, and various external factors often lead users to check whether their actual speed matches the provider's advertised rates. This guide will walk you through the correct way to measure internet speed, the best tools for the job, and the key factors that can influence your results.

Speedtest – The Standard for Measuring Internet Speed

One of the most popular services for internet speed testing is Speedtest.net by Ookla. This tool allows users to measure speed directly from a web browser or via dedicated applications for different devices.

For Windows and macOS users, the web-based version is the easiest option.
For server administrators, a CLI version of Speedtest is available for remote testing.

Installing and Running Speedtest CLI

For testing on a remote server, follow these steps:

Download the utility:
wget https://install.speedtest.net/app/cli/ookla-speedtest-1.2.0-linux-x86_64.tgz
Extract the archive:
tar zxvf ookla-speedtest-1.2.0-linux-x86_64.tgz speedtest
Run the test:
./speedtest

After running the test, the utility will display a detailed report on your connection speed.

Important Considerations

The accuracy of speed tests depends on multiple factors. Even if your home internet shows great results, speed to a specific server may vary. To get the most reliable results, consider the following:

Test speed from different geographic locations.
Choose a testing server that is closer to your location.
Run multiple tests to eliminate temporary fluctuations.

Why Avoid Third-Party Speed Testing Tools?

There are many alternative tools available, such as speedtest-cli, but these often lack proper maintenance and updates.

Key issues with outdated utilities:

The last update for speedtest-cli was more than five years ago, making it unreliable.
Default repositories in Debian-based systems often contain outdated versions.
Older versions may use an outdated server list, leading to inaccurate results.

Since Speedtest's infrastructure is constantly evolving, using the official Speedtest CLI ensures the most accurate results.

Factors That Affect Internet Speed Test Results

1. Distance to the Test Server

Geographic location plays a critical role. Internet connections rely on a series of routers and network cables, meaning:

The more network nodes between you and the test server, the higher the latency.
A longer route may reduce your effective speed.

For example, if you test speed to a server in the US while located in China, the results may be significantly lower than your provider’s advertised speed.

2. Load on the Testing Server

The Speedtest server you connect to may be under heavy load due to multiple users running tests simultaneously.

Some Speedtest servers impose speed limits, such as:

1 Mbps cap
1 Gbps cap
No speed limits

If you have a 10 Gbps internet connection but the test server is capped at 1 Gbps, your results will not reflect your true speed.

3. Load on Your Own Server or Device

If you're testing speed on a remote server, its internal performance may impact results. Factors that could slow down speed tests include:

High CPU load
Slow disk performance
Insufficient RAM
Limited number of available file descriptors

Recommended steps before testing:

Stop all resource-intensive processes.
Check system resources to ensure they are not maxed out.

Additional Network Diagnostics

For a more in-depth analysis of your connection, use the MTR tool, available on most Linux distributions.

To run an MTR diagnostic:

mtr example.com

MTR can help diagnose:

Packet loss at specific routers.
High latency at certain network nodes.
Network instability caused by congested routes.

If packet loss occurs at one router and persists further down the route, the issue may be caused by your ISP’s network congestion.

The Impact of Wi-Fi and Mobile Networks on Speed

Wireless networks (Wi-Fi, 4G, 5G) are susceptible to external factors, which can distort speed test results.

Common wireless issues:

Interference from household devices (microwaves, power tools, etc.).
Overloaded Wi-Fi access points reducing available bandwidth.
Fluctuating mobile signals affecting network stability.

For more accurate speed tests, always use a wired connection whenever possible.

Conclusion

Accurately measuring internet speed requires a careful approach. Follow these best practices to ensure reliable results:

Use the official Speedtest CLI or Ookla’s web version.
Test speed from multiple locations to get a more comprehensive view.
Verify the load on the test server before running a speed test.
Use MTR for detailed network diagnostics.
Avoid Wi-Fi and mobile networks when testing for the most accurate results.

By following these recommendations, you can obtain the most precise speed test results and assess the true quality of your internet connection.