The reliability of a broadband speed test can depend on various factors, including the server locations, the methodology used, and the server’s capacity to handle high traffic. Here are some popular and reputable speed test websites that were considered reliable as of my last update:

1. Ookla Speedtest (www.speedtest.net): Ookla is one of the most well-known speed test providers globally. They have servers in various locations worldwide, including several servers in South Africa. It’s widely used and generally considered reliable.
2. MyBroadband Speed Test (speedtest. my broadband.co.za): MyBroadband is a popular technology website in South Africa, and their speed test tool is specifically designed for users in the country. It is known for providing accurate results.
3. Vodacom Broadband Speed Test (www.vodacom.co.za/vodacom/services/internet-services/speed-test): Vodacom is a major telecommunications company in South Africa, and their speed test tool is designed to test the broadband speed for their customers.
4. MWEB Speed Test (www.mweb.co.za/services/speedtest): MWEB is an Internet Service Provider in South Africa, and their speed test is another option you can consider for testing your broadband speed.

Remember that while these speed tests are generally reliable, various factors can affect your results, including the time of day, network congestion, and the device you are using for the test. To get the most accurate measurement, ensure you close all other applications using the internet during the test, and preferably connect your device directly to the router via an Ethernet cable.