How to Use Google Speed Test and How It Differs from Fast.com

Published: 2026-11-12 / Author: Yuki Nakazawa

If you search Google for "internet speed test", you can measure your connection speed right inside the search results. This article first explains how to use Google's speed test and how to read the results.

It then compares Fast.com, Speedtest.net, ISP-branded tests and this site, explains why the results often disagree, and suggests which tool fits which purpose. It does not declare any tool the best. It only states facts that could be confirmed on each provider's official pages.

How to use and read Google's speed test

Google's speed test is provided by Google in partnership with Measurement Lab (M-Lab). M-Lab is a collaborative project that publishes internet measurement data for research.

How to use it

  1. Search on Google. Google's help page describes searching for "internet speed test".
  2. Click "Run speed test" in the search results.
  3. The result appears in about 30 seconds.

The help page does not say what appears for searches in other wordings or languages. It also notes that the test is not available in some countries and regions.

How to read the results

The test shows three values: download speed (Mbps), upload speed (Mbps) and latency (ms). Latency is the time it takes for data to be sent and a response to come back. It affects games and video calls. This site uses the following common thresholds.

ItemToo slow / poorStandard / goodPlenty / very good
DownloadUnder 10 Mbps10–30 Mbps30 Mbps or more (100 Mbps or more is fast)
UploadUnder 5 Mbps5–10 Mbps10 Mbps or more
Ping (latency)50 ms or more20–50 msUnder 20 ms

More detailed guidelines are in What Is a Good Internet Speed? How to Read Speed Test Results and What Is a Good Ping? Jitter Explained and How to Lower Ping.

Things to keep in mind

  • The upper limit is 700 Mbps. The help page states that on faster connections the result may show lower than the actual speed. Keep this in mind on plans such as 1 Gbps fiber.
  • Data usage per test is about 4.4 MB outside the US (about 9.4 MB inside the US). On a mobile connection, data charges may apply.
  • Your IP address is shared with M-Lab. M-Lab publishes test results, including IP addresses, for research.

M-Lab's standard test, NDT (current version ndt7), runs over WebSocket (a mechanism that lets the browser and server exchange data in both directions) and uses a single TCP connection. By specification, each direction is measured for at most 10 seconds. However, Google's help page does not say whether the test in the search results uses exactly this method.

Comparing the main speed test tools

The table below summarizes the differences between the main tools. Where a provider's help or official pages do not cover a point, it is marked "not stated" or "not published".

ItemGoogle (M-Lab)Fast.comSpeedtest.netThis site
ProviderPartnership between Google and M-LabNetflixOokla (a subsidiary of Ziff Davis)Run by an individual
Method and number of connectionsNot stated in the help page (M-Lab's NDT uses WebSocket and one connection)Multiple transfers to and from Netflix servers. The settings screen has a field for the number of parallel connectionsMainly TCP (port 8080) with multiple connections, adding connections during the test as needed. HTTP is a fallbackOpen-source LibreSpeed (LGPLv3)
Test serversNot stated in the help page (M-Lab's privacy policy says data is usually collected by the nearest server)Netflix servers. Locations and selection method are not publishedA network of servers run by ISPs and others. Pings up to 5 nearby servers and picks the one with the shortest ping. Can be changed manuallyOur own server in Sapporo plus public mirrors in 37 locations worldwide; the one with the lowest ping is chosen automatically (usually "Tokyo" from Honshu, Japan's main island)
Displayed valuesDownload, upload, latencyDownload (upload and latency under "Show more info"). Unloaded and loaded latencyDownload, upload, ping, jitter. Ping in three stages: idle, during upload, during downloadDownload, upload, ping, jitter
AppsNot stated in the help page (run from search results)Yes (iOS and Android, "FAST Speed Test")Yes (iPhone, iPad, Mac, Apple TV, Android, Windows)No (measures in the browser)
Ads and data handlingIP address shared with M-Lab. M-Lab publishes results including IP addressesThe FAQ states there are no ads. Collects IP addresses, measurements and more; states that it does not sell personal informationThe official help states the site shows ads (including interest-based ads via ad networks)No ads or third-party trackers
LoginNot stated as requiredNot stated as requiredNot required. Creating an account lets you keep all your results in one placeNot required

Speedtest.net's help pages are not consistent about the number of servers: one page says "more than 5,500" and another says "about 3,000". How this site works is also described in Privacy Policy and About.

ISP- and carrier-branded speed tests

Many internet providers and mobile carriers offer their own speed test. These tests usually measure to a server inside the provider's own network. Because the data does not have to leave that network or cross the wider internet, the result tends to read higher than a test to an outside server. It shows how fast your line is up to the provider, but not necessarily how fast the sites and services you actually use will feel.

Such a test is useful as one reference point, for example when you report a problem to your provider. Keep in mind that a provider can change or withdraw its own test at any time, so it is better not to rely on it as your only tool for long-term records.

Why results differ between tools

Even on the same connection, the numbers can differ widely from tool to tool. There are four main reasons.

  • Different server locations. The farther the server, the higher the ping and the harder it is to reach full speed. Speedtest.net's help also explains that distant servers tend to give slower results.
  • Different numbers of connections. A method that uses only one connection and a method that combines several can give very different results, especially on fast lines.
  • Different limits and calculations. Google's limit is 700 Mbps. Speedtest.net drops some of the fastest and slowest values before averaging.
  • Different devices, browsers and Wi-Fi. On fast lines, a device's wireless performance and the browser are said to make a difference.

When comparing, the basic rule is to use the same device, the same connection and the same time of day. The steps are explained in detail in How to Run an Accurate Speed Test: Steps and How Many Times.

Which tool to use for what

PurposeSuitable approach
Just a quick checkRun it from Google's search results, or simply open Fast.com. Both let you measure as soon as the page opens
Checking whether video will play smoothlyFast.com is provided by Netflix and measures speed to Netflix servers. By this site's thresholds, 30 Mbps or more download is the guideline for 4K video
Checking ping for gamingUse a tool that lets you choose a nearby server, and check ping and jitter. By this site's thresholds, ping under 20 ms is "very good" and jitter under 10 ms is "stable"
Tracking over timeChoose a tool whose test server does not change each time, and record results under the same conditions at different times of day. Speedtest.net lets you keep a history with an account

Do not judge from a single result from a single tool. Measuring a few times with two or more tools shows the trend more clearly. You are welcome to use this site's Free Speed Test as one of the tools you compare.

FAQ

How do I use Google's speed test?

Search Google for something like "internet speed test" and click "Run speed test" in the results. Download, upload and latency appear in about 30 seconds.

Is Google's speed test accurate?

Its help page says the test has an upper limit of 700 Mbps, so faster connections may show lower results. Results also change with server location and time of day. Comparing several tools makes it easier to judge.

Can Fast.com measure upload speed?

Yes. At first only download is shown. Click "Show more info" to see upload and latency.

Why does my ISP's own speed test show higher numbers?

An ISP's own test usually measures to a server inside its network, so the data does not travel across the wider internet. That tends to give higher numbers than a test to an outside server. Use it as one reference alongside other tools.

Why do results differ between tools?

Because the server location, number of connections and calculation method differ between tools. Compare on the same device at the same time of day.

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