The ultimate speed test test 2021 (75 Mbps)

The best free online speed tests

TL;DR

Based on our test results of 2021 we concluded that if your advertised download speed is 75 Mbps, it's best to use a mainstream speed test like Cloudflare or Samknows.

Probably the best speed test for this speed is the realistic speed test SpeedOf.me.

 

Contents

  1. Introduction
  2. What is the best?
  3. Method of measurement
  4. Speed tests to test
  5. The results
  6. Conclusions
 

Introduction

In 2021 we knew, based on previous speed test tests (2020 and 2020 updated), the true internet speed we have and the factors that influence a speed test.

In addition, we thought that the bias of a speed test is the most important factor to test. Therefore, this speed test originally focused on the biases of the speed tests.

Nowadays we know how to calculate an accuracy score and that there are indeed several catagories of speed tests.

Hence we updated this page (in 2025) with our new insights.

 

What is the best?

Originally it was assumed that the best speed test has the lowest bias. Nowadays, we use the accuracy score instead of bias.

 

Method of measurement

Based on an earlier tests, we know that our true internet speed is 84 Mbps (our ISP used has increased the download speed from 50 to 75 Mbps in 2021).

Each speed test is tested at least 5 times with a clean browser on a wired Linux desktop.

 

Speed tests to test

For this speed test test all unique speed tests we where aware of are tested.

 

The results

The following has been measured (and calculated). Note that all values in Mbps.

  1. Bandwidth Place 70.00, 69.91, 69.91, 70.00, 70.08. Standard deviation: 0.07, median: 70.00, accuracy score: 20
  2. Broadband Internet Speed test (Gone) No meaningful results
  3. Broadband Speed Checker 74.83, 74.95, 74.85, 74.41, 75.00. Standard deviation: 0.23, median: 74.85, accuracy score: 98
  4. Cloudflare 75.4, 75.2, 75.5, 75.1, 75.4. Standard deviation: 0.2, median: 75.4, accuracy score: 100 Mainstream
  5. Comparitech 78.68, 81.30, 81.09, 80.89, 82.54. Standard deviation: 1.40, median: 81.09, accuracy score: 53
  6. DSLReports 75.2, 75.1, 73.8, 76.6, 76.3. Standard deviation: 1.1, median: 75.2, accuracy score: 99 Mainstream
  7. Fast 76, 63, 64, 52, 69. Standard deviation: 9, median: 64, accuracy score: 20
  8. Fireprobe 76.18, 76.43, 76.16, 76.38, 76.25. Standard deviation: 0.12, median: 76.25, accuracy score: 98 Mainstream
  9. Google Fiber 76.1, 76.4, 76.4, 75.9, 76.4. Standard deviation: 0.2, median: 76.4, accuracy score: 98 Mainstream
  10. Internet Speed at a Glance 50..100, 50..100, 50..100, 50..100, 50..100. Standard deviation: -, median:-, accuracy score: 20
  11. LibreSpeed 80.2, 81.0, 80.7, 80.8, 80.8. Standard deviation: 0.3, median: 80.8, accuracy score: 34
  12. M-Lab 75.96, 76.05, 75.87, 76.56, 76.10. Standard deviation: 0.27, median: 76.05, accuracy score: 99 Mainstream
  13. Meter.net 75.05, 74.86, 74.98, 74.72, 75.24. Standard deviation: 0.20, median: 74.98, accuracy score: 99 Mainstream
  14. nPerf 77.22, 77.11, 77.37, 77.66, 77.38. Standard deviation: 0.21, median: 77.37, accuracy score: 89 Mainstream
  15. Speedtest 74.29, 73.52, 74.23, 74.02, 74.50. Standard deviation: 0.37, median: 74.23, accuracy score: 94
  16. OpenSpeedTest™ 79.26, 79.38, 79.19, 78.11, 79.45. Standard deviation: 0.55, median: 79.26, accuracy score: 20
  17. RCN Speedtest (nowadays Astound) 77, 77, 65, 77, 77. Standard deviation: 5, median: 77, accuracy score: 94 Mainstream
  18. Samknows 76.4, 76.4, 76.4, 76.4, 76.4. Standard deviation: 0.0, median: 76.4, accuracy score: 98 Mainstream
  19. SpeedOf.me 83.44, 83.52, 83.50, 83.42, 83.52. Standard deviation: 0.05, median: 83.50, accuracy score: 99 Realistic
  20. SpeedSmart 81.61, 79.23, 76.25, 78.31, 78.56. Standard deviation: 1.93, median: 78.56, accuracy score: 50
  21. Speedtest4.PHP No meaningful results
  22. TestMy.net 77.3, 76.9, 77.1, 76.8, 76.7. Standard deviation: 0.2, median: 76.9, accuracy score: 95 Mainstream
  23. Toast 53.2, 71.2, 71.8, 71.5, 70.7. Standard deviation: 8.1, median: 71.2, accuracy score: 20
  24. Xfinity Speed Test 82.7, 79.2, 77.9, 77.2, 79.5. Standard deviation: 2.1, median: 79.2, accuracy score: 20

Previously we concluded that the max value of SpeedOf.me was most accurate. Hence we also measured these values:

  1. SpeedOf.me (max) 83.48, 83.52, 83.55, 83.52, 83.53. Standard deviation: 0.03, median: 83.52, accuracy score: 99 Realistic
 

Conclusions

Our original conclusions (based on measuring the bias) were:

  1. Every speed test has a negative bias
  2. Since almost every ISP vendor uses or recommends an Ookla-based speed test and the fact that the Ookla Speedtest has a negative bias of -10.5%, we can only conclude that the ISPs have agreed to provide a 12% higher bandwidth than what is advertised.
  3. When the Chromium browser is throtteld at 30 Mbps, the real download speed is 34.0 Mbps
  4. When the Firefox browser is throtteld at 30 Mbps (Wi-Fi), the real download speed is 34.4 Mbps

In addition, we nowadays conclude that with an advertised speed of 75 Mbps:

  1. Only Cloudflare has an accuracy score of 100
  2. Four speed tests have an accuracy score of 99. These speed tests are: DSLReports, M-Lab, Meter.net and SpeedOf.me
  3. Of these five speed tests SpeedOf.me is most consistent (has the lowest standard deviation)
  4. Of all speed tests SamKnows is most consistent with a standard deviaton of 0.0
  5. There are 9 mainstream speed tests (Astound, Cloudflare, DSLReports, Fireprobe, Google Fiber, M-Lab, Meter.net, nPerf, SamKnows and TestMy.net)
  6. SpeedOf.me is the only realistic speed test

When your advertised download speed is 75 Mbps, there are plenty of good (mainstream) speed tests.

Based on these results we recommend the following speed tests:

  1. Cloudflare Mainstream (highest accuracy score)
  2. Samknows Mainstream (accurate and very consistent)
  3. SpeedOf.me Realistic (accurate and very consistent)