MLab Internet Speed Test by Google - a more accurate internet speed test

Legacy Internet Speed Test Explained

Most internet speed tests base are based on traditional measurement of downloading a single stream (large file download). This is not a true representation of start/stop internet mixed traffic like your browser.

Most of us are most test internet speed while browsing sites.  A typical browser loads thousands of mini files (html, css, js, media files) when you visit a page. 

Now adays, even traditional single file videos streams are chunked into smaller pieces, so single file download test is outdated.  Below picture, are files loaded when watching a Youtube.com video. 

Enter, a modern traffic internet speed therefore was needed, enter M-Lab Tests - M-Lab (measurementlab.net)

Legacy Internet Speed Test

Speed test by Ookla (used by all internet providers) measures only continuous single stream (large file download) but is not a true representation of start/stop internet mixed traffic like your browser.

I am contracted with Rogers for 1.5Mbps Down, 50Mbps up, and this lines up conveniently, but my internet is slow. 

MLab internet speed test is block internally by Rogers support, when I recently called technician about my slow internet! 
 

Modern Internet Speed Test

The Measurement Lab test sponsored by Google, uses mixed traffic. MSAK measures multi-stream traffic focused on throughput and latency, while NDT focuses on single-stream upload/download speeds and network diagnostics. MSAK is a more realistic internet traffic measurement.

Do ⇨ MLab Internet Speed Test

The MSAK test is more accurate load test that more accurately represents browsing websites. 

		NDT	MSAK
	Test Server	Toronto, CA	Toronto, CA
	Download	409.85 Mb/s	711.61 Mb/s
	Upload	17.36 Mb/s	5.87 Mb/s
	Latency	38 ms	20 ms
	Retransmission	0.23%	0.00%

Modern Internet Speed Test Explained

MSAK (Measurement Swiss-Army Knife)

MSAK is a measurement service hosted by M-Lab that implements two different test protocols:

• throughput: A configurable Websocket-based throughput measurement protocol capable of multi-stream tests. Its design is partially based on M-Lab’s single-stream measurement protocol, NDT. Configurable parameters currently include:
  • Number of streams
  • Congestion control algorithm
  • Test duration
  • Per-stream byte limit
• latency: A UDP-based latency measurement protocol.

This is measurement is more reflective of website browsing traffic.

NDT (Network Diagnostic Tool)

NDT is a single stream performance measurement of a connection’s capacity for “bulk transport” (as defined in IETF’s RFC 3148). NDT reports upload and download speeds and latency metrics.

This is more like a traditional test; a more technical test used to for diagnosing issues with the network. 

Copilot Comparison

🔍 Key Differences

Feature	MSAK	NDT
Measurement Type	Throughput (multi-stream) + Latency	Throughput (single-stream) + Diagnostics
Protocols Used	WebSocket (TCP), UDP	TCP (BBR, Cubic, Reno)
Configurability	High (streams, duration, CCA)	Low (standardized test)
Diagnostic Depth	Basic latency + throughput	Detailed TCP-level diagnostics
Target Audience	Researchers, engineers'	General users, policymakers

MSAK (Measurement Swiss-Army Knife)

Purpose: A flexible tool for measuring throughput and latency using configurable protocols.

• Throughput Test:

  • Uses a WebSocket-based protocol.

  • Supports multi-stream testing.

  • Configurable parameters include:

    • Number of streams

    • Congestion control algorithm

    • Test duration

    • Per-stream byte limits

• Latency Test:

  • Uses a UDP-based protocol to measure network latency.

• Use Case: Ideal for researchers or engineers needing customizable network performance tests across multiple dimensions (e.g., congestion control behavior, stream concurrency).

NDT (Network Diagnostic Tool)

Purpose: Measures single-stream performance for bulk data transport, focusing on upload/download speeds and latency.

• Metrics Reported:

  • Upload speed

  • Download speed

  • Latency (RTT)

  • Congestion indicators

  • TCP-level diagnostics (e.g., loss rate, retransmissions)

• Protocols:

  • ndt7: Uses TCP BBR or Cubic, operates over HTTP(S) ports.

  • ndt5: Legacy support using Cubic.

  • web100: Deprecated, used Reno TCP.

• Use Case: Best for users wanting a quick, standardized snapshot of their internet connection’s performance, especially for consumer advocacy or policy analysis.