How Internet Speed Tests Work

Understanding how internet speed tests work helps you interpret results accurately and troubleshoot connection issues. This guide explains the technical process behind speed testing and what each measurement means for your internet experience.

The Speed Test Process

Step 1: Server Connection

When you initiate a speed test, your browser connects to our testing servers. We automatically select the optimal server based on your location and network routing to ensure accurate measurements. For South African users, this typically means connecting to servers within the country to minimize external factors.

Step 2: Latency Measurement (Ping)

Before measuring speeds, we test your connection's latency by sending small data packets to our server and measuring how long they take to return. This round-trip time, measured in milliseconds, indicates your connection's responsiveness. Lower ping times mean better responsiveness for real-time applications like gaming and video calls.

What is Good Latency?
  • Excellent: Under 20ms
  • Good: 20-50ms
  • Average: 50-100ms
  • Poor: Over 100ms

Step 3: Download Speed Test

The download test measures how quickly data travels from the internet to your device. We initiate multiple simultaneous connections to our servers and download test files. The test typically runs for 10-15 seconds, measuring the total amount of data transferred and calculating your speed in megabits per second (Mbps).

Our testing methodology uses multiple parallel connections because modern internet connections can handle multiple simultaneous data streams. This approach more accurately reflects real-world usage where you might be streaming video, downloading files, and browsing simultaneously.

Understanding Your Results

Download Speed (Mbps)

Download speed represents how fast your internet can retrieve data from the internet. This affects:

What Download Speeds Mean for Different Activities

Ping/Latency (ms)

Ping measures response time rather than throughput. While download speed tells you how much data you can receive, ping tells you how quickly that data starts arriving. This is crucial for:

Why Results Vary

Network Congestion

Internet speeds fluctuate based on network usage. During peak hours (typically 7-11 PM), when many users are online, speeds may decrease due to congestion on your ISP's network or at interconnection points. Running tests at different times helps identify patterns.

WiFi vs Ethernet

Wireless connections typically show lower speeds than wired connections due to:

For the most accurate speed test, use a wired Ethernet connection directly to your router.

Device Limitations

Your device's hardware can impact test results. Older devices, especially those with older WiFi adapters or limited processing power, may not achieve the full speeds your connection supports. Mobile devices particularly may show lower speeds due to hardware constraints.

Background Activity

Applications running on your device or network can consume bandwidth and affect test results. Before testing:

Technical Details

How We Calculate Speed

Speed is calculated using this formula: Speed (Mbps) = (Data Transferred in bits) / (Time in seconds) / 1,000,000

For example, if 200 megabits of data transfers in 10 seconds: 200,000,000 bits / 10 seconds / 1,000,000 = 20 Mbps

Why Multiple Tests Matter

Network conditions change constantly. Running multiple tests at different times provides a better picture of your connection's typical performance. We recommend:

Server Selection Impact

The physical distance between you and the test server affects results. We optimize server selection for South African users, but factors like routing paths and peering agreements between networks can influence measurements. Our system automatically selects the best available server for your location.

Accuracy and Reliability

What Affects Accuracy

Several factors can impact test accuracy:

Improving Test Accuracy

For the most reliable results:

  1. Use a wired Ethernet connection when possible
  2. Close all other applications and browser tabs
  3. Disable VPN and proxy services
  4. Run tests at different times
  5. Use the same testing location consistently
  6. Ensure no one else is using your network

Comparing with Advertised Speeds

ISPs advertise "up to" speeds because various factors affect actual performance. It's normal to see speeds slightly below advertised rates due to protocol overhead, network conditions, and equipment limitations. However, if you consistently get significantly lower speeds (less than 80% of advertised), contact your ISP.

Important Note: ISPs advertise speeds in megabits per second (Mbps), while downloads typically show in megabytes per second (MB/s). To convert: divide Mbps by 8 to get MB/s. For example, 100 Mbps = approximately 12.5 MB/s.

Using Test Results

Troubleshooting Slow Speeds

If tests show consistently low speeds:

  1. Restart your router and modem
  2. Check for firmware updates
  3. Scan for malware on your device
  4. Test with different devices
  5. Contact your ISP with test results

Planning for Upgrades

Use your test results to determine if you need a faster connection. If you regularly experience buffering, slow downloads, or lag during important activities, your current speeds may be insufficient for your usage patterns.

Run Your Speed Test