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3 Key Metrics for Successful Web Application Performance - NBA Edition Part 3

Jean Tunis

Start with 3 Key Metrics for Successful Web Application Performance - NBA Edition Part 1

Start with 3 Key Metrics for Successful Web Application Performance - NBA Edition Part 2

In Part 2 of this 3-part blog series, I talked about the second metric to look at when performing a study of your website or web application, like I'm doing with the Knicks website. In this final blog of the series, I finish up with the most important metric of all – the one visitors care about – response time.

Metric #3: Response Time

Response time is the time that it takes for a request to be executed from the client application, across the network, processed by the server, and a response is returned. This time is typically measured in the number of seconds that a request takes.

If your site's response time is in the milliseconds, you're likely doing pretty great! Congratulations!

Or, you must be testing from a local environment – which you must always be careful with when it comes to web applications.

But for me, I didn't get milliseconds when I tested the Knicks site. With a FIOS connection, it took the site about 7.7 seconds to be fully loaded by the WebPageTest machine's Chrome browser.

The great thing with WebPageTest is that I can get more detail about this 7.7 seconds.

I can see that while it took my request to nyknicks.com about 7.7 seconds to fully load, it takes over 9 seconds for it to become visually complete. It also takes the site about 3 seconds before I can start to see anything being rendered in the browser.

So what's behind all these different response times? When it comes to web performance, response time is usually broken up into three parts - client response time, network response time, and server response time.

Let's discuss client response time.

Client Response Time

The client is the one making the requests to fulfill whatever it is the user is looking to accomplish. In my case, the client is the Chrome browser that I selected in WebPageTest.

However, when the user makes a request, there may be a number of things the client needs to do in order to process that request.

For example, when a user clicks on a link that is to present to them some text, the client must process the text to display it on the screen. It must be able to determine whether the text that was received is actually readable text that can be rendered in the browser.

It must also process any image received from the server.

For one, if the image is compressed, the client must run its compression algorithm to decompress this image and return it to its original size. Then, once the image has been decompressed, it must be rendered.

So the client must be able to determine what kind of image it is and then display this onto the screen.

All of this takes time for the client to process, and is very dependent on the hardware and software resources available to be able to process this as fast as possible.

So that is the client response time.

How to Get Client Response Time from WebPageTest: WebPageTest doesn't give the client response time breakdown directly. It does, however, provide a graph of the CPU processing occurring on the test machine.

With this information, you can see how certain requests are causing additional processing time on the client. This helps identify which requests you need to tweak to reduce this response time.

Now let's talk about server response time.

Server Response Time

Keeping with the example above, when the server gets a request from the client, it must figure out how to fulfill this request. The time that it takes to do this is the server response time.

Just like the client, the server is processing the request sent by the user through the client. It must look for the location of the text information that was requested. It must also locate the file containing the image that was asked for.

On the Knicks website, the client asks for a lot of images, so the server needs to locate these images and send them to the browser. Once they are found – which takes time to process – the server sends the response back to the client for display to the user. If the server has to get this information from a database, it must now take the time to convert that request to an appropriate SQL query to pull the data out of the database. Then it must wait for the database server to return a response to its request. From the standpoint of the client, all of this processing time is the server's response time.

The more hardware and software resources the server has available, the faster it can process these requests, and therefore, reduce its response time.

Don't Forget the Tiers ...

But, if it's waiting for the database server – or some other server – to return a response for its request before it can fulfill the client's request, the server is now relying on the database's response time as well.

If the two servers are close in distance to each other or are on the same machine, this time is likely to be largely made up of processing time. But if they're not close, this processing time will also include the time it takes for the request to travel the distance between the two servers.

How to Get Server Response Time from WebPageTest: I can't directly get server response time from WebPageTest, but I can use the First Byte Time that is provided to help give me a sense of any server-related issues that may need to be further investigated. First Byte Time is the time that it takes the client to receive the first byte of a response to its request to the server. So if there are any requests with high First Byte Time response times, this is something to look into as a potential server concern.

In my test of the Knicks site, I can see that an image of the Knicks Kristaps Porzingis dunking the basketball had a 229ms First Byte Time.

Given that the image was not compressed, why would it take that long for it to be processed?

And if the web application and database servers are not close in distance, not only are you looking at the processing on the server, you should also be looking at the connectivity between the application and database servers.

Maybe that's what happening on the back-end of the Knicks site.

This leads to the third piece of response time – network response time.

Network Response Time

When the client sends its request over to the server and waits for the response, the biggest portion of overall response time is usually most impacted by the distance between the two. This distance is composed of the network and all of its parts. Ideally, you want the distance between the client and server to be as close as can be, but in this global world of commerce, that's not always possible. With content delivery network providers, like Akamai, Amazon Cloudfront, and others, clients and servers can be closer than before. But there still is a distance, and you must account for that.

Main Parts of Network Time

There are four main parts to network response time.

You have processing – just like on the client and server. This is the time it takes for any device along the network path to process the data that it receives to determine where this data is going and how to get it to its next stop and ultimately to its destination.

You have queuing. This is the time that the data sent is waiting in a device's queue along the path between the client and the server before it can be transmitted.

You have serialization. This is the time that it takes to put the bits of data onto the network connections along the path that the data must traverse.

And finally, you have propagation. This is the time that it takes the bits of data sent to travel from one side to the other side.

What Can Be Improved

Serialization is the component of response time that can be improved by increasing available bandwidth.

I mentioned that I used a FIOS connection in WebPageTest that makes 20Mbps available. I also ran a separate test with a slower speed using DSL, to resemble my ISP connection.


With the FIOS connection, I only get to peak available bandwidth use a couple times or so during the test.

But with DSL, I am consistently reaching the peak bandwidth throughout the test. This is partly why the fully loaded response time for the DSL connection was over 51 seconds, compared to the 7.7 seconds on the FIOS connection!

Generally, all of the parts of network response time can be changed with better technology. You can increase the bandwidth to improve serialization, you can add more memory to improve queuing, or you can increase CPU to improve processing.

But there's little you can do to improve propagation time. This time can only be manipulated by adding a CDN or implementing WAN optimization, but not necessarily changed because the distance between client and server is still the same. If the CDN, for example, doesn't have something cached and available to send to the client, it must go all the way back to the server to get it.

Physics strikes again!

All In Together Now!

All of these components of response time affect how a user will perceive how fast your website or web application is. Higher times from either of those components obviously means high response times. And that could mean "goodbye, visitor and potential customer."

As for me and the Knicks, it's not quite "goodbye." It's more like "see you later."

If the performance of the team or its website was a true indication of fandom, I'd be following another team a long time ago. But it's not.

Are all your website's visitors fanatics? Probably not!

And That's the Bottom Line

So there it is! The three web performance metrics that you should look at when investigating or planning for performance issues with your websites and web applications.

Don't forget – The keys to successful web application performance are to find ways to reduce your response time and all of its components, minimize the number of requests the client sends, and limit the amount of data going to the client.

Your users, customers, and visitors expect fast performing web experiences. And unless they're a true, true fan of the Knicks, like I am, you'll probably lose them if you don't follow these keys.

Don't lose them! I think the Knicks have done enough losing for all of us in the last few years.

There's always high hopes at the beginning of each season for my Knicks – like I have now. There might not be for your web application.

Now I have a question for you: What do you focus on to ensure good web performance for you sites and applications?

The Latest

According to Auvik's 2025 IT Trends Report, 60% of IT professionals feel at least moderately burned out on the job, with 43% stating that their workload is contributing to work stress. At the same time, many IT professionals are naming AI and machine learning as key areas they'd most like to upskill ...

Businesses that face downtime or outages risk financial and reputational damage, as well as reducing partner, shareholder, and customer trust. One of the major challenges that enterprises face is implementing a robust business continuity plan. What's the solution? The answer may lie in disaster recovery tactics such as truly immutable storage and regular disaster recovery testing ...

IT spending is expected to jump nearly 10% in 2025, and organizations are now facing pressure to manage costs without slowing down critical functions like observability. To meet the challenge, leaders are turning to smarter, more cost effective business strategies. Enter stage right: OpenTelemetry, the missing piece of the puzzle that is no longer just an option but rather a strategic advantage ...

Amidst the threat of cyberhacks and data breaches, companies install several security measures to keep their business safely afloat. These measures aim to protect businesses, employees, and crucial data. Yet, employees perceive them as burdensome. Frustrated with complex logins, slow access, and constant security checks, workers decide to completely bypass all security set-ups ...

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In 2025, enterprise workflows are undergoing a seismic shift. Propelled by breakthroughs in generative AI (GenAI), large language models (LLMs), and natural language processing (NLP), a new paradigm is emerging — agentic AI. This technology is not just automating tasks; it's reimagining how organizations make decisions, engage customers, and operate at scale ...

In the early days of the cloud revolution, business leaders perceived cloud services as a means of sidelining IT organizations. IT was too slow, too expensive, or incapable of supporting new technologies. With a team of developers, line of business managers could deploy new applications and services in the cloud. IT has been fighting to retake control ever since. Today, IT is back in the driver's seat, according to new research by Enterprise Management Associates (EMA) ...

In today's fast-paced and increasingly complex network environments, Network Operations Centers (NOCs) are the backbone of ensuring continuous uptime, smooth service delivery, and rapid issue resolution. However, the challenges faced by NOC teams are only growing. In a recent study, 78% state network complexity has grown significantly over the last few years while 84% regularly learn about network issues from users. It is imperative we adopt a new approach to managing today's network experiences ...

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From growing reliance on FinOps teams to the increasing attention on artificial intelligence (AI), and software licensing, the Flexera 2025 State of the Cloud Report digs into how organizations are improving cloud spend efficiency, while tackling the complexities of emerging technologies ...

3 Key Metrics for Successful Web Application Performance - NBA Edition Part 3

Jean Tunis

Start with 3 Key Metrics for Successful Web Application Performance - NBA Edition Part 1

Start with 3 Key Metrics for Successful Web Application Performance - NBA Edition Part 2

In Part 2 of this 3-part blog series, I talked about the second metric to look at when performing a study of your website or web application, like I'm doing with the Knicks website. In this final blog of the series, I finish up with the most important metric of all – the one visitors care about – response time.

Metric #3: Response Time

Response time is the time that it takes for a request to be executed from the client application, across the network, processed by the server, and a response is returned. This time is typically measured in the number of seconds that a request takes.

If your site's response time is in the milliseconds, you're likely doing pretty great! Congratulations!

Or, you must be testing from a local environment – which you must always be careful with when it comes to web applications.

But for me, I didn't get milliseconds when I tested the Knicks site. With a FIOS connection, it took the site about 7.7 seconds to be fully loaded by the WebPageTest machine's Chrome browser.

The great thing with WebPageTest is that I can get more detail about this 7.7 seconds.

I can see that while it took my request to nyknicks.com about 7.7 seconds to fully load, it takes over 9 seconds for it to become visually complete. It also takes the site about 3 seconds before I can start to see anything being rendered in the browser.

So what's behind all these different response times? When it comes to web performance, response time is usually broken up into three parts - client response time, network response time, and server response time.

Let's discuss client response time.

Client Response Time

The client is the one making the requests to fulfill whatever it is the user is looking to accomplish. In my case, the client is the Chrome browser that I selected in WebPageTest.

However, when the user makes a request, there may be a number of things the client needs to do in order to process that request.

For example, when a user clicks on a link that is to present to them some text, the client must process the text to display it on the screen. It must be able to determine whether the text that was received is actually readable text that can be rendered in the browser.

It must also process any image received from the server.

For one, if the image is compressed, the client must run its compression algorithm to decompress this image and return it to its original size. Then, once the image has been decompressed, it must be rendered.

So the client must be able to determine what kind of image it is and then display this onto the screen.

All of this takes time for the client to process, and is very dependent on the hardware and software resources available to be able to process this as fast as possible.

So that is the client response time.

How to Get Client Response Time from WebPageTest: WebPageTest doesn't give the client response time breakdown directly. It does, however, provide a graph of the CPU processing occurring on the test machine.

With this information, you can see how certain requests are causing additional processing time on the client. This helps identify which requests you need to tweak to reduce this response time.

Now let's talk about server response time.

Server Response Time

Keeping with the example above, when the server gets a request from the client, it must figure out how to fulfill this request. The time that it takes to do this is the server response time.

Just like the client, the server is processing the request sent by the user through the client. It must look for the location of the text information that was requested. It must also locate the file containing the image that was asked for.

On the Knicks website, the client asks for a lot of images, so the server needs to locate these images and send them to the browser. Once they are found – which takes time to process – the server sends the response back to the client for display to the user. If the server has to get this information from a database, it must now take the time to convert that request to an appropriate SQL query to pull the data out of the database. Then it must wait for the database server to return a response to its request. From the standpoint of the client, all of this processing time is the server's response time.

The more hardware and software resources the server has available, the faster it can process these requests, and therefore, reduce its response time.

Don't Forget the Tiers ...

But, if it's waiting for the database server – or some other server – to return a response for its request before it can fulfill the client's request, the server is now relying on the database's response time as well.

If the two servers are close in distance to each other or are on the same machine, this time is likely to be largely made up of processing time. But if they're not close, this processing time will also include the time it takes for the request to travel the distance between the two servers.

How to Get Server Response Time from WebPageTest: I can't directly get server response time from WebPageTest, but I can use the First Byte Time that is provided to help give me a sense of any server-related issues that may need to be further investigated. First Byte Time is the time that it takes the client to receive the first byte of a response to its request to the server. So if there are any requests with high First Byte Time response times, this is something to look into as a potential server concern.

In my test of the Knicks site, I can see that an image of the Knicks Kristaps Porzingis dunking the basketball had a 229ms First Byte Time.

Given that the image was not compressed, why would it take that long for it to be processed?

And if the web application and database servers are not close in distance, not only are you looking at the processing on the server, you should also be looking at the connectivity between the application and database servers.

Maybe that's what happening on the back-end of the Knicks site.

This leads to the third piece of response time – network response time.

Network Response Time

When the client sends its request over to the server and waits for the response, the biggest portion of overall response time is usually most impacted by the distance between the two. This distance is composed of the network and all of its parts. Ideally, you want the distance between the client and server to be as close as can be, but in this global world of commerce, that's not always possible. With content delivery network providers, like Akamai, Amazon Cloudfront, and others, clients and servers can be closer than before. But there still is a distance, and you must account for that.

Main Parts of Network Time

There are four main parts to network response time.

You have processing – just like on the client and server. This is the time it takes for any device along the network path to process the data that it receives to determine where this data is going and how to get it to its next stop and ultimately to its destination.

You have queuing. This is the time that the data sent is waiting in a device's queue along the path between the client and the server before it can be transmitted.

You have serialization. This is the time that it takes to put the bits of data onto the network connections along the path that the data must traverse.

And finally, you have propagation. This is the time that it takes the bits of data sent to travel from one side to the other side.

What Can Be Improved

Serialization is the component of response time that can be improved by increasing available bandwidth.

I mentioned that I used a FIOS connection in WebPageTest that makes 20Mbps available. I also ran a separate test with a slower speed using DSL, to resemble my ISP connection.


With the FIOS connection, I only get to peak available bandwidth use a couple times or so during the test.

But with DSL, I am consistently reaching the peak bandwidth throughout the test. This is partly why the fully loaded response time for the DSL connection was over 51 seconds, compared to the 7.7 seconds on the FIOS connection!

Generally, all of the parts of network response time can be changed with better technology. You can increase the bandwidth to improve serialization, you can add more memory to improve queuing, or you can increase CPU to improve processing.

But there's little you can do to improve propagation time. This time can only be manipulated by adding a CDN or implementing WAN optimization, but not necessarily changed because the distance between client and server is still the same. If the CDN, for example, doesn't have something cached and available to send to the client, it must go all the way back to the server to get it.

Physics strikes again!

All In Together Now!

All of these components of response time affect how a user will perceive how fast your website or web application is. Higher times from either of those components obviously means high response times. And that could mean "goodbye, visitor and potential customer."

As for me and the Knicks, it's not quite "goodbye." It's more like "see you later."

If the performance of the team or its website was a true indication of fandom, I'd be following another team a long time ago. But it's not.

Are all your website's visitors fanatics? Probably not!

And That's the Bottom Line

So there it is! The three web performance metrics that you should look at when investigating or planning for performance issues with your websites and web applications.

Don't forget – The keys to successful web application performance are to find ways to reduce your response time and all of its components, minimize the number of requests the client sends, and limit the amount of data going to the client.

Your users, customers, and visitors expect fast performing web experiences. And unless they're a true, true fan of the Knicks, like I am, you'll probably lose them if you don't follow these keys.

Don't lose them! I think the Knicks have done enough losing for all of us in the last few years.

There's always high hopes at the beginning of each season for my Knicks – like I have now. There might not be for your web application.

Now I have a question for you: What do you focus on to ensure good web performance for you sites and applications?

The Latest

According to Auvik's 2025 IT Trends Report, 60% of IT professionals feel at least moderately burned out on the job, with 43% stating that their workload is contributing to work stress. At the same time, many IT professionals are naming AI and machine learning as key areas they'd most like to upskill ...

Businesses that face downtime or outages risk financial and reputational damage, as well as reducing partner, shareholder, and customer trust. One of the major challenges that enterprises face is implementing a robust business continuity plan. What's the solution? The answer may lie in disaster recovery tactics such as truly immutable storage and regular disaster recovery testing ...

IT spending is expected to jump nearly 10% in 2025, and organizations are now facing pressure to manage costs without slowing down critical functions like observability. To meet the challenge, leaders are turning to smarter, more cost effective business strategies. Enter stage right: OpenTelemetry, the missing piece of the puzzle that is no longer just an option but rather a strategic advantage ...

Amidst the threat of cyberhacks and data breaches, companies install several security measures to keep their business safely afloat. These measures aim to protect businesses, employees, and crucial data. Yet, employees perceive them as burdensome. Frustrated with complex logins, slow access, and constant security checks, workers decide to completely bypass all security set-ups ...

Image
Cloudbrink's Personal SASE services provide last-mile acceleration and reduction in latency

In MEAN TIME TO INSIGHT Episode 13, Shamus McGillicuddy, VP of Research, Network Infrastructure and Operations, at EMA discusses hybrid multi-cloud networking strategy ... 

In high-traffic environments, the sheer volume and unpredictable nature of network incidents can quickly overwhelm even the most skilled teams, hindering their ability to react swiftly and effectively, potentially impacting service availability and overall business performance. This is where closed-loop remediation comes into the picture: an IT management concept designed to address the escalating complexity of modern networks ...

In 2025, enterprise workflows are undergoing a seismic shift. Propelled by breakthroughs in generative AI (GenAI), large language models (LLMs), and natural language processing (NLP), a new paradigm is emerging — agentic AI. This technology is not just automating tasks; it's reimagining how organizations make decisions, engage customers, and operate at scale ...

In the early days of the cloud revolution, business leaders perceived cloud services as a means of sidelining IT organizations. IT was too slow, too expensive, or incapable of supporting new technologies. With a team of developers, line of business managers could deploy new applications and services in the cloud. IT has been fighting to retake control ever since. Today, IT is back in the driver's seat, according to new research by Enterprise Management Associates (EMA) ...

In today's fast-paced and increasingly complex network environments, Network Operations Centers (NOCs) are the backbone of ensuring continuous uptime, smooth service delivery, and rapid issue resolution. However, the challenges faced by NOC teams are only growing. In a recent study, 78% state network complexity has grown significantly over the last few years while 84% regularly learn about network issues from users. It is imperative we adopt a new approach to managing today's network experiences ...

Image
Broadcom

From growing reliance on FinOps teams to the increasing attention on artificial intelligence (AI), and software licensing, the Flexera 2025 State of the Cloud Report digs into how organizations are improving cloud spend efficiency, while tackling the complexities of emerging technologies ...