Before diving into Cloudflare’s speed test, let’s take a moment to understand what a speed test actually is. There’s no one definition of what Internet “speed” means, but what people are typically referring to is the measurement of throughput or the rate at which data is sent between sender and receiver within a network. Throughput is typically expressed in mega or gigabits per second (Mbps or Gbps), which are units that end users are usually familiar with, due to how commercial Internet Service Providers (ISPs) often market their packages (500 Mbps, 1 Gbps, increasingly 10 Gbps and so on). In light of this popular association, speed tests are typically designed to send data until the maximum throughput of a connection is met.

Most speed tests are run from end user devices such as laptops, mobile phones and sometimes routers, but where the test sends data to, meaning where the server is in the network, differs from test to test. These variances can impact results dramatically. For example, consider a user in New York City running one speed test that sends data to New Jersey, while another connects to a server in Singapore. Even if both tests use the exact same methodology, their results will differ noticeably due to the distance they have to travel and the network links they have to cross to get there. 

Server locations are one of many ways speed tests vary from one another. They may also differ in how the test decides to send more data, the number of TCP/UDP streams it opens to send data, which congestion control algorithm it uses, how it aggregates the samples it collects, etc. Each of these decisions influences what the end user sees as their final “speed”. It is also common for speed tests to measure latency, packet loss and sometimes latency variation (jitter), though as important as they are, and as we’ll discuss in more detail below, these metrics are not always intuitive for end users to understand. 

Speed tests gained popularity in the early days of the Internet, when bandwidth was the primary obstacle to a quality end user experience. But as the Internet has progressed and its use cases have expanded, bandwidth has become less of a limitation and, in some geographies, almost plentiful. Now, other challenges that can degrade your video calls or gaming sessions, such as latency under load (bufferbloat) and packet loss, have become the industry focus as key metrics to optimize when improving Internet connectivity. Nevertheless, speed tests remain a valuable tool for assessing Internet quality, in part because of their popularity with end users. Speed tests are by far the most well-known kind of Internet measurement and for that reason, Cloudflare is proud to provide one.

When you visit Cloudflare’s Speed Test, results start appearing right away. That’s because as soon as the page loads, your browser begins sending data requests to Cloudflare’s Network Quality API and recording how long each exchange takes. The API runs on Cloudflare’s global network using Workers, leveraging our anycast architecture to automatically route you to the nearest data center.

Unlike many other speed test methodologies that focus on absolute maximum throughput, Cloudflare’s Speed Test doesn’t try to saturate your connection. Instead, it sends a series of data payloads of predefined sizes—what we call data blocks—to assess your connection’s quality under more realistic usage patterns. Each data block is transmitted a fixed number of times, and once the sequence completes, the detailed results are displayed in box-and-whisker plots to show the observed ranges and percentiles.

To generate each individual result, we record the time it takes to establish the connection and the time required for the data transfer to finish, subtracting any server “thinking time”. Establishing a connection involves exchanging individual packets back and forth and happens as quickly as network latency permits, while the data transfer time is limited by network bandwidth, congestion, server limits, and even the amount of data transferred—perhaps surprisingly, smaller transfers also have their throughput limited by network latency.

As throughput measurements run, the test also sends empty requests at regular intervals to measure loaded latency: the round-trip time (RTT) it takes for data to travel to Cloudflare’s network and back while your connection is busy. Loaded latency differs from idle latency, which measures RTT to Cloudflare’s network when no data is being transferred. Idle latency is recorded first, as soon as the page loads, and reflects the lowest expected latency. The test also measures loaded and idle jitter, the average variation between consecutive RTT measurements—reflecting network stability—and packet loss, the percentage of packets that fail to reach their destination when relayed through a WebRTC TURN server over a period of time.

Throughout the test, you can watch the aggregate results for each metric update in real time, but the final result isn’t calculated until all test sequences are complete. Once they are, the full set of measurements is used to compute an Aggregated Internet Measurement (AIM) score—a metric designed to translate your connection’s performance into end-user-friendly terms, such as how well it supports streaming, gaming, or video conferencing. The AIM score provides a convenient summary of overall performance, but in this deep dive, we’ll focus on what the detailed Cloudflare Speed Test results actually tell you—and what they don’t—about your Internet connection.

A defining feature of Cloudflare’s Speed Test is that it runs on Cloudflare’s own global network. Other speed test providers place their servers closer to end users or major exchange points to capture how the network performs under specific conditions. Cloudflare’s Speed Test, however—and any test built on our Network Quality API—measures performance in a context that mirrors what users actually do every day: accessing content delivered through Cloudflare’s network.

Additionally, since Cloudflare’s Speed Test does not strive to saturate a user’s connection, its download and upload tests do not technically measure maximum throughput, but rather the rate at which you can reliably expect to send various sizes of data. While this may seem like a small distinction, it means that Cloudflare’s Speed Test is not trying to show what your connection is capable of at its peak, but rather what it typically delivers—its quality.

Day to day, most users are not maximizing their available bandwidth. Video conferencing, streaming, web browsing, and even gaming all require minimal bandwidth and are much more sensitive to latency, jitter, and packet loss. In other words, achieving a high score on a throughput-saturating speed test—one that mirrors the service level you purchased from your ISP—does not necessarily equate to a high-quality online experience. The finer details of which metrics matter most for evaluating network quality depend on individual use cases. For example, a gamer might benefit more from lower latency (lower lag), while a remote worker may benefit more from lower jitter (smoother video conferencing). For the majority of modern use cases, throughput is just one of many metrics that contribute to a quality Internet connection

It’s also important to note that Cloudflare’s Speed Test runs primarily from an end-user device, within the browser. As a result, its measurements include potential bottlenecks beyond the access network—such as the browser itself, the local Wi-Fi network, and other factors. This means the results don’t solely reflect the performance of your ISP, but rather the combined performance of all components along the path to the content.

It’s common for end users to run speed tests to check whether they’re getting the Internet service they pay for. While that’s a perfectly reasonable question, there’s no standardized definition for how to answer it. This means that no speed test—including Cloudflare’s—is a definitive measure of ISP service. However, it is a helpful resource for assessing the quality of experience when accessing content delivered by Cloudflare’s vast global network.

In this section, we’ll interpret the results from two speed test examples: the first test scoring “Great” on all three network quality rubrics, and the second scoring a mere “Average”. In your own tests, you may get a consistent score, or you may get different scores for video streaming, online gaming and video chatting, depending on how well-balanced your Internet connection is over these three use cases.

From these scores we already get a high-level interpretation of the test results. You can expect consistently good quality from the “Great” connection and reasonable quality with occasional glitches from the “Average” connection – but to understand why, we must look at the numbers.

This test ran from a laptop connected over Wi-Fi inside a single-family home served by a 500 Mbps residential fiber connection, and we can already see that we can’t quite reach the contracted download speed, topping off at 406 Mbps. The culprit here is Wi-Fi, which is usually the bottleneck on high-speed connections, and a common cause of observable instability.

But here we can see that we’re probably in an area of the house with good reception and without significant activity from neighboring Wi-Fi networks (the two most common causes of poor Wi-Fi). We can tell from the relatively consistent shape of the download and upload graphs, and from the low jitter.

The latency is well within what’s expected in an urban area (and could be 2 milliseconds lower by switching to a wired connection), and the difference between the numbers at idle and the numbers while loaded (downloading or uploading) is relatively small. This means you can expect to attend a video call while your files synchronize to and from your cloud drive of choice in the background, without any glitches. Large differences between the idle and loaded numbers are a common indicator of a poor connection—if you observe differences approaching 100 milliseconds or more over a wired connection, your ISP is likely at fault.

Higher-bandwidth connections should display lower idle to loaded latency differences. The higher the bandwidth, the less likely it is to be fully utilized in practice. However, congestion further upstream in the network can drive these numbers up, especially if your ISP is oversubscribing its capacity.

You might be wondering why the download and upload graphs start slow and ramp up. This happens because data transfers progressively send more packets at once for each required acknowledgment, starting by one acknowledgment for each packet. The consequence is that small data transfers are limited in speed by latency—the longer it takes for a packet to reach its destination, the longer it takes the acknowledgment packet to make its way back to the sender, and the longer it takes for the next data packet to be sent.

If you’re technically inclined, you may enjoy learning about congestion control algorithms, but that topic alone can fill entire books. For now, you can see this effect in the charts for each download size: transfers smaller than 10 MB can’t utilize the full bandwidth of this connection.

If you’re left wondering if this means that your normal day-to-day web browsing, composed primarily of relatively small data transfers, is mostly unable to fully utilize the available bandwidth above a certain level, then you have successfully grasped one of the reasons why pure speed is no longer the main indicator of quality of experience in modern broadband connections.

The second test ran from the same laptop using a cellular 5G connection, and the results are very different. The speeds are much lower and inconsistent over time, the latency numbers are higher (especially under load), and the latency jitter is quite high.

From the download and upload speeds we can guess that we’re probably not in a densely populated area—in areas of dense 5G coverage you can expect higher speeds and lower latencies. On the other hand, in densely populated areas you can also expect more people to be using the network at the same time, driving speeds down and latencies up (due to congestion). From the detailed latency charts we can observe how irregular latencies are in this case, with some numbers above 100 milliseconds. 

Connection quality and convenience are often at odds with each other. The convenience of being able to access the Internet from anywhere in your house, or from a park or the beach, comes with quality tradeoffs. The Cloudflare Speed Test reports allows you to better understand those tradeoffs, compare your results against your peers or other available providers, and make more informed choices.

Cloudflare provides its speed test to empower end users with greater insight into their connectivity and to help improve the Internet by offering transparency into how it performs. The engine that runs the test is open source, which means that anyone can use our speed test to facilitate their own research and can always verify how the results are produced. To enable researchers, policymakers, network operators, and other stakeholders to analyze Internet connectivity, all results from Cloudflare’s Speed Tests are published to Measurement Lab’s public Internet measurement dataset in BigQuery and are also accessible through Cloudflare’s Radar API. We share this data to advance open Internet research, but every result is anonymized to protect user privacy and is never used for commercial purposes.

Originally developed in 2020, Cloudflare’s speed test has become a go-to resource for measuring end user network quality. In particular, we receive a lot of positive feedback about its easy-to-understand user interface and the metrics that it reports alongside throughput.

But at Cloudflare, we are always improving – so here’s what we’re planning to make Cloudflare’s speed test even better.

Increased Measurement

We’re continuing to expand the reach and scalability of Cloudflare’s Network Quality API to make it easier for third parties to integrate and use. Our goal is to empower customers to measure their users' connectivity by utilizing Cloudflare's network. We’re already proud to partner with UNICEF, which uses Cloudflare’s Speed Test as part of its Giga project to connect every school in the world to the Internet, and with Orb, which enables end users to continuously monitor the quality of their Internet connections from any platform or device using Cloudflare’s Network Quality API as part of its diagnostic measurement suite. Throughout 2026, we plan to significantly increase the number of third parties using our Speed Test and Network Quality API to power their own measurement tools and initiatives.

Additional Capabilities

To make the Speed Test more valuable for third parties, we’re also developing new capabilities that enable more detailed performance analysis. This includes support for higher throughput measurements—which, while not the sole indicator of connection quality, remain important for diagnosing network performance, especially in enterprise or shared-office environments where multiple users share the same connection. These enhancements will help make our platform a more comprehensive tool for understanding and improving network health.

Improved Diagnostics

Many users turn to speed tests not only to verify that they’re getting the service they’ve paid for, but also to diagnose connectivity issues. We want to make that diagnostic process even more effective. Our goal is to expose richer metrics and more advanced functionality to help users answer key questions, such as: Where’s the bottleneck? Is it within my local network or my ISP’s? Does this issue occur only with specific applications? Is it unique to me, or are others in my region experiencing it too? By providing deeper insight into these questions, we aim to make Cloudflare’s Speed Test a more powerful tool for understanding and improving real-world Internet performance.

Try running a Cloudflare Speed Test to test your connectivity today by visiting speed.cloudflare.com.

We relentlessly measure our own performance and our performance against peers. We publish those results routinely, starting with our first update in June 2021 and most recently with our last post in September 2024.

Today’s update breaks down where we have improved since our update last year and what our priorities are going into the next year. While we are excited to be the fastest in the greatest number of last-mile ISPs, we are never done improving and have more work to do.

We measure network performance by attempting to capture what the experience is like for Internet users across the globe. To do that we need to simulate what their connection is like from their last-mile ISP to our networks.

We start by taking the 1,000 largest networks in the world based on estimated population. We use that to give ourselves a representation of real users in nearly every geography.

We then measure performance itself with TCP connection time. TCP connection time is the time it takes for an end user to connect to the website or endpoint they are trying to reach. We chose this metric because we believe this most closely approximates what users perceive to be Internet speed, as opposed to other metrics which are either too scientific (ignoring real world challenges like congestion or distance) or too broad.

We take the trimean measurement of TCP connection times to calculate our metric. The trimean is a weighted average of three statistical values: the first quartile, the median, and the third quartile. This approach allows us to reduce some of the noise and outliers and get a comprehensive picture of quality.

For this year’s update, we examined the trimean of TCP connection times measured from August 6 to September 4, Cloudflare is the #1 provider in 40% of the top 1000 networks. In our September 2024 update, we shared that we were the #1 provider in 44% of the top 1000 networks.

The TCP Connection Time (Trimean) graph shows that we are the fastest TCP connection time in 383 networks, but that would make us the fastest in 38% of the top 1,000. We exclude networks that aren’t last-mile ISPs, such as transit networks, since they don’t reflect the end user experience, which brings the number of measured networks to 964 and makes Cloudflare the fastest in 40% of measured ISPs and the fastest across the top networks.

A Cloudflare-branded error page does more than just display an error; it kicks off a real-world speed test. Behind the scenes, on a selection of our error pages, we use Real User Measurements (RUM), which involves a browser retrieving a small file from multiple networks, including Cloudflare, Amazon CloudFront, Google, Fastly and Akamai.

Running these tests lets us gather performance data directly from the user's perspective, providing a genuine comparison of different network speeds. We do this to understand where our network is fastest and, more importantly, where we can make further improvements. For a deeper dive into the technical details, the Speed Week blog post covers the full methodology.

By using RUM data, we track key metrics like TCP Connection Time, Time to First Byte (TTFB), and Time to Last Byte (TTLB). These are widely recognized, industry-standard metrics that allow us to objectively measure how quickly and efficiently a website loads for actual users. By monitoring these benchmarks, we can objectively compare our performance against other networks.

We specifically chose the top 1000 networks by estimated population from APNIC, excluding those that aren’t last-mile ISPs. Consistency is key: by analyzing the same group of networks in every cycle, we ensure our measurements and reporting remain reliable and directly comparable over time.

The map below shows the fastest providers per country and Cloudflare is fastest in dozens of countries. 

The color coding is generated by grouping all the measurements we generate by which country the measurement originates from. Then we look at the trimean measurements for each provider to identify who is the fastest… Akamai was measured as well, but providers are only represented in the map if they ranked first in a country which Akamai does not anywhere in the world.

These slim margins mean that the fastest provider in a country is often determined by latency differences so small that the fastest provider is often only faster by less than 5%. As an example, let’s look at India, a country where we are currently the second-fastest provider.

In India, Cloudflare is 5ms behind Cloudfront, the #1 provider (To put milliseconds into perspective, the average human eye blink lasts between 100ms and 400ms). The competition for the number one spot in many countries is fierce and often shifts day by day. For example, in Mexico on Tuesday, August 5th, Cloudflare was the second-fastest provider by 0.73 ms but then on Tuesday, August 12th, Cloudflare was the fastest provider by 3.72 ms. 

Because ranking reorderings are common, we also review country and network level rankings to evaluate and benchmark our performance. 

As mentioned above, in September 2024, Cloudflare was fastest in 44% of measured ISPs. These values can shift as providers constantly make improvements to their networks. One way we focus in on how we are prioritizing improving is to not just observe where we are not the fastest but to measure how far we are from the leader.

In these locations we tend to pace extremely close to the fastest provider, giving us an opportunity to capture the spot as we relentlessly improve. In networks where Cloudflare is 2nd, over 50% of those networks have a less than 5% difference (10ms or less) with the top provider.

In networks where Cloudflare is 3rd, 50% of those networks are less than a 10% difference with the top provider (10ms or less). Margins are small and suggest that in instances where Cloudflare isn’t number one across networks, we’re extremely close to our competitors and the top networks change day over day. 

Countries with an abundance of networks, like the United States, have a lot of noise we need to calibrate against. For example, the graph below represents the performance of all providers for a major ISP like AS701 (Verizon Business).

_{AS701 (Verizon Business) Connect Time (P95) between 2025-08-09 and 2025-09-09}

In this chart, the “P95” value, or 95th percentile, refers to one point of a percentile distribution. The P95 shows the value below which 95% of the data points fall and is specifically good at helping identify the slowest or worst-case user experiences, such as those on poor networks or older devices. Additionally, we review the other numbers lower on the percentile chain in the table below, which tell us how performance varies across the full range of data. When we do so, the picture becomes more nuanced.

At the 95th percentile for AS701, Cloudflare ranks 4th but at the 75th and 50th, Cloudflare is only 2 milliseconds slower than the fastest provider. In other words, when reviewing more than one point along the distribution at the network level, Cloudflare is keeping up with the top providers for the less extreme samples. To capture these details, it’s important to look at the range of outcomes, not just one percentile.

To better reflect the full spectrum of user experiences, we started using the trimean in July 2025 to rank providers. This metric combines values from across the distribution of data - specifically the 75th, 50th and 25th percentiles - which gives a more balanced representation of overall performance, rather than only focusing on the extremes. Summarizing user experience with a single number is always challenging, but the trimean helps us compare providers in a way that better reflects how users actually experience the Internet.

Cloudflare is the fastest provider in 40% of networks in the majority of real-world conditions, not just in worst-case scenarios. Still, the 95th percentile remains key to understanding how performance holds up in challenging conditions and where other providers might fall behind in performance. When we review the 95th percentile across the same date range for all the networks, not just AS701, Cloudflare is fastest across roughly the same amount of networks but by 103 more networks than the next fastest provider. Being faster in such a wide margin of networks tells us that Cloudflare is particularly strong in the challenging, long-tail cases that other providers struggle with.

Our performance data shows that even when we are not the top-ranked provider, we remain exceptionally competitive, often trailing the leader by a mere handful of percentage points. Our strength at the 95th percentile also highlights our superior performance in the most challenging scenarios. Cloudflare’s ability to outperform other providers, in the worst-case, is a testament to the resilience and efficiency of our network.

Moving forward, we'll continue to share multiple metrics and continue to make improvements to our network —and we’ll use this data to do it! Let’s talk about how. 

Cloudflare applies this data to identify regions and networks that need prioritization. If we are consistently slower than other providers in a network, we want to know why, so we can fix it.

For example, the graph below shows the 95th percentile of Connect Time for AS8966. Prior to June 13, 2025, our performance was suffering, and we were the slowest provider for the network. By referencing our own measurement data, we prioritized partner data centers in the region and almost immediately performance improved for users connecting through AS8966.

Cloudflare’s partner data centers consist of collaborations with local service providers who host Cloudflare's equipment within their own facilities. This allows us to expand our network to new locations and get closer to users more quickly. In the case of AS8966, adding a new partner data center took us from being ranked last to ranked first and improved latency by roughly 150ms in one day. By using a data-driven approach, we made our network faster and most importantly, improved the end user experience.

_{TCP Connect Time (P95) for AS8966}

We are always working to build a faster network and will continue sharing our process as we go. Our approach is straightforward: identify performance bottlenecks, implement fixes, and report the results. We believe in being transparent about our methods and are committed to a continuous cycle of improvement to achieve the best possible performance. Follow our blog for the latest performance updates as we continue to optimize our network and share our progress.