An Internet speed test measures the network bandwidth
(and sometimes latency
) of your connection by using sample data files and test Web servers. You can use these speed test services to measure your download speeds and verify the Internet service provider is supplying you the expected amount of bandwidth. These tools can also help you measure the results of any performance enhancements (tweaks) you may make to your network setup.
You can choose from among many Internet servers distributed worldwide to run this download / upload speed test. The Speedtest.net service utilizes single large file transfers and is therefore good for measuring total network bandwidth but does not give as much information about network latency effects. It boasts a cool Flash interface for displaying results. Some other popular speed test services on the Internet - like Speakeasy - are based on the Speedtest.net technology.
This service is provided by the U.S. Federal Communications Commission. It measures four parameters of an Internet connection: download speed, upload speed, latency, and jitter (the amount of variation in latency). Besides presenting a results report, the broadband.gov test also stores all results into a national database "to analyze broadband quality and availability on a geographic basis across the United States."
DSL Reports offers multiple speed test services. Their Flash-based application supports standard broadband speed testing while an alternative Java applet promises better accuracy on very high-speed connections. Other tests are designed for mobile phones.
These tests are among the few available that report on latency (in milliseconds) as well as upload / download bandwidth. However, the Flash test in particular may under-report the bandwidth score if your computer has a slow CPU. Be sure to compare these results to another service that does not use a Flash interface.
Unlike the others listed, this service is available as standalone Windows utility program rather than through Web pages. This allows the test to execute more efficiently especially on older computers. Although this utility originated in the UK, it now works well with a pool of test servers maintained globally.
CNET Bandwidth Meter is one of the oldest download speed test services on the Internet. Based on the type of connection you specify, the test will download one image file of size between 50 KB and 1.5 MB to calculate download bandwidth. It uses a fixed server location in the U.S. Do not attempt to re-run the test using the browser's Back button as results will be unreliable.
Note that MSN hosts an Internet Speed Test service that is powered by this same CNET test engine.
Bandwidth Place offers this Bandwidth Speed Test free for use up to three times per month as well as a subscription option for more frequent testing and reporting. This service provides a download only test based on 1 MB file sizes. This service prompts you for geographic location and type of Internet service to compare your results against averages of other visitors.
Better known in academia, this tool from a U.S government lab was designed to probe a network connection for faulty connections and bottlenecks. This service uses a simple Java applet interface and offers only one server location to test against. It reports both measured download and upload bandwidth after a short (20 second) run.