Skip to main content

20 Top Factors That Impact Website Response Time - Part 2

APMdigest asked industry experts – from analysts and consultants to the top vendors – to outline the most important factors that impact website response time. The second installment of the list, featuring factors 6–10, covers the front end.

Start with Part 1 of "20 Top Factors That Impact Website Response Time"

6. WEB PAGE SIZE

In my experience, the single most consistent factor that contributes to slower load times is page size. All other things being equal, a fatter page is a slower page. In one study I conducted of 60 popular sites that used responsive design, only 20% rendered acceptably quickly — and these were also the only sites that were less than 1 MB in size. According to the HTTP Archive, the average web page today is more than 2 MB in size. This is something site owners should be aware of, and concerned about.
Tammy Everts
Senior Researcher & Evangelist, SOASTA

7. RESPONSIVE WEB DESIGN

Mobilegeddon already is upon us where Google gives higher priority for websites that are mobile friendly. Hence, the new race is to build websites that use responsive web design techniques. This could create performance problems if resources, such as images, are not properly managed. For example, including all variations of images (for tablet, desktop, mobile, retina display) in a CSS and including this CSS incorrectly in the webpage can end up loading all variations of the image in the background for every request, hence slowing down overall page load time.
Gibu Mathew
Director of Product Management, Site24x7

8. JAVASCRIPT

Radware has been studying the various factors that impact website response time for years. Aside from a steady increase in the volume of data required for each page, one of the largest impacts that we are seeing comes from the increasing dependency on JavaScript. When these scripts block execution or download slowly the overall site performance is directly impacted.
Kent Alstad
VP of Acceleration, Radware

14 Best Practices to Cure Your Website’s Performance Pains

9. WEB CONTENT AND CODE

As more and more code resides on the browser side as opposed to server side, one of the top factors impacting website response time is un-optimized browser side content like download of large images, no caching, too many redirects or DNS lookups. Using APM tools, you can see a very granular breakdown of end user response time from the browser and determine the bottleneck at a glance. You can see exactly how much time was spent on resolving DNS lookups, how much time was spent in downloading content, time spent in load event scripts and so forth. It is essential that developers fine tune their browser side code following best practices, cross test across browser types, devices and platforms, and keep an eye on the end user experience with predictive alerts to prevent slow downs.
Payal Chakravarty
Sr. Product Manager - APM, IBM

The top factor that affects website response time is full page load time. Nothing harms the user experience more than slow loading times, especially when multimedia, Flash, or other graphics are involved. Users will leave your site if the video they want to view won't load. Slow load times can be caused by content-heavy pages and poor code on the website side, or inadequate bandwidth on the user side. To ensure website performance, IT can use ping requests and loading time measurements (specifically, the time it takes to download source code) to track page speed. It is often simple to fix problems that cause slow load times, but it is critical to effectively measure what load times are across each browser and on mobile devices to understand when your website is performing poorly.
Amanda Karkula
Channel Sales Manager, Paessler AG

10. N+1 QUERIES

N+1 queries are a common web application anti-pattern that can cause slow website response time. It happens when a single application query runs other queries “automatically” - resulting in multiple queries running at once. For example, a user may be browsing through a photo gallery and while switching from one picture to another, comments get rendered along with the photos. To diagnose, N+1 issues, look into the log data - if you see one query for photos and one for "comments" generated for every photo returned by the original query, you've got an N+1 query on your hands.
Trevor Parsons
Chief Scientist, Logentries

Read Part 3 of "20 Top Factors That Impact Website Response Time"

The Latest

Pilots are everywhere, stakeholders are seeking results, businesses are pushing for new tools, and IT teams are being asked to make AI secure, reliable, and useful at scale. But as organizations move from testing AI to operationalizing it, many are discovering that the biggest barrier is not the model, the use case, or even the budget. It is the file data foundation within ...

Fast or cheap? For most of my career in engineering, speed and quality sat on opposite ends of a seesaw. The "OR" in "fast or cheap" was non-negotiable. It was expected that pushing for faster releases meant that something in quality would give way. Tightening quality controls meant the schedule slipped. Every engineering leader I know has lived some version of that tradeoff ... The seesaw is starting to level out ...

I have been building enterprise software for more than 20 years ... One thing stays true across all of it: You do not find out your foundation is wrong during the crisis. You find out when the debt comes due. For a lot of organizations, that bill is arriving now. New research ... puts hard numbers on something practitioners have been sensing for a while. The telemetry problem isn't coming. It's already here ...

The rapid growth of AI workloads is pushing traditional log management approaches to their limits, according to The State of Log Management 2026 report from Dynatrace. Modern logs have become critical to understanding, validating, and securing AI-driven decisions, helping organizations ensure reliability, compliance, and performance at scale. However, the volume and complexity of AI telemetry are overwhelming legacy tools ...

For years, secure connectivity has relied on a familiar pattern: route traffic back to centralized gateways, inspect it, and then allow access. This model worked when applications lived in a handful of data centers and users were largely confined to offices. That model is now under strain. Applications are distributed across clouds, users connect from everywhere, and real-time workloads demand performance that centralized inspection points struggle to deliver. As traffic volumes grow and latency expectations shrink, routing everything through a small number of control points has become both a performance bottleneck and a resilience risk. The future of secure connectivity requires a different approach ...

The AI experimentation phase is over, and the private cloud is where enterprise AI workloads are being deployed for security and scale, according to Private Cloud Outlook 2026, a new report from Broadcom ... 2026 marks an acceleration into a full AI tipping point. The shift is being shaped by three forces — costs, complexity, and control — that public cloud environments are increasingly failing to address for production AI at scale. Key findings from the report include ...

44% of organizations have reported an outage in the past year tied to suppressed or ignored alerts, and 78% had at least one incident where no alert was fired at all ... Engineers learned about failures from customers. That gap between what our tools report and what our customers experience is the problem DevOps teams have been quietly solving with GenAI tooling, even as most enterprises continue to run their NOCs on manual alert triage ...

Cloud outages are usually described as technical failures. When a service goes down, a dependency breaks, or a region has issues, the focus immediately shifts to infrastructure. But if you look closely at how these incidents actually unfold, the root cause is rarely the technology itself. It is almost always tied to decisions made earlier, during design, implementation, or day-to-day operations. The system behaves the way it was built. The real question is how it was built ...

77% of leaders say their teams need AI skills urgently. 64% say their organization plans to train current employees rather than hire new ones. So far, so reasonable. The part that surprised me is who's been put in charge: 34% of those leaders say IT and engineering own the AI skills mandate. Learning and Development or HR own it at 7% of organizations. That's roughly five-to-one in favor of the people who understand the tools, over the people whose actual job is teaching adults how to learn new ones ...

In the ever-evolving digital landscape, enterprises are increasingly focused on enhancing their observability stacks to gain deeper insights into their IT environments. Observability has become a cornerstone of modern IT operations, enabling organizations to monitor, diagnose, and optimize their systems with unprecedented precision. However, a critical piece of the puzzle often goes unnoticed in this transformation: IBM i ...

20 Top Factors That Impact Website Response Time - Part 2

APMdigest asked industry experts – from analysts and consultants to the top vendors – to outline the most important factors that impact website response time. The second installment of the list, featuring factors 6–10, covers the front end.

Start with Part 1 of "20 Top Factors That Impact Website Response Time"

6. WEB PAGE SIZE

In my experience, the single most consistent factor that contributes to slower load times is page size. All other things being equal, a fatter page is a slower page. In one study I conducted of 60 popular sites that used responsive design, only 20% rendered acceptably quickly — and these were also the only sites that were less than 1 MB in size. According to the HTTP Archive, the average web page today is more than 2 MB in size. This is something site owners should be aware of, and concerned about.
Tammy Everts
Senior Researcher & Evangelist, SOASTA

7. RESPONSIVE WEB DESIGN

Mobilegeddon already is upon us where Google gives higher priority for websites that are mobile friendly. Hence, the new race is to build websites that use responsive web design techniques. This could create performance problems if resources, such as images, are not properly managed. For example, including all variations of images (for tablet, desktop, mobile, retina display) in a CSS and including this CSS incorrectly in the webpage can end up loading all variations of the image in the background for every request, hence slowing down overall page load time.
Gibu Mathew
Director of Product Management, Site24x7

8. JAVASCRIPT

Radware has been studying the various factors that impact website response time for years. Aside from a steady increase in the volume of data required for each page, one of the largest impacts that we are seeing comes from the increasing dependency on JavaScript. When these scripts block execution or download slowly the overall site performance is directly impacted.
Kent Alstad
VP of Acceleration, Radware

14 Best Practices to Cure Your Website’s Performance Pains

9. WEB CONTENT AND CODE

As more and more code resides on the browser side as opposed to server side, one of the top factors impacting website response time is un-optimized browser side content like download of large images, no caching, too many redirects or DNS lookups. Using APM tools, you can see a very granular breakdown of end user response time from the browser and determine the bottleneck at a glance. You can see exactly how much time was spent on resolving DNS lookups, how much time was spent in downloading content, time spent in load event scripts and so forth. It is essential that developers fine tune their browser side code following best practices, cross test across browser types, devices and platforms, and keep an eye on the end user experience with predictive alerts to prevent slow downs.
Payal Chakravarty
Sr. Product Manager - APM, IBM

The top factor that affects website response time is full page load time. Nothing harms the user experience more than slow loading times, especially when multimedia, Flash, or other graphics are involved. Users will leave your site if the video they want to view won't load. Slow load times can be caused by content-heavy pages and poor code on the website side, or inadequate bandwidth on the user side. To ensure website performance, IT can use ping requests and loading time measurements (specifically, the time it takes to download source code) to track page speed. It is often simple to fix problems that cause slow load times, but it is critical to effectively measure what load times are across each browser and on mobile devices to understand when your website is performing poorly.
Amanda Karkula
Channel Sales Manager, Paessler AG

10. N+1 QUERIES

N+1 queries are a common web application anti-pattern that can cause slow website response time. It happens when a single application query runs other queries “automatically” - resulting in multiple queries running at once. For example, a user may be browsing through a photo gallery and while switching from one picture to another, comments get rendered along with the photos. To diagnose, N+1 issues, look into the log data - if you see one query for photos and one for "comments" generated for every photo returned by the original query, you've got an N+1 query on your hands.
Trevor Parsons
Chief Scientist, Logentries

Read Part 3 of "20 Top Factors That Impact Website Response Time"

The Latest

Pilots are everywhere, stakeholders are seeking results, businesses are pushing for new tools, and IT teams are being asked to make AI secure, reliable, and useful at scale. But as organizations move from testing AI to operationalizing it, many are discovering that the biggest barrier is not the model, the use case, or even the budget. It is the file data foundation within ...

Fast or cheap? For most of my career in engineering, speed and quality sat on opposite ends of a seesaw. The "OR" in "fast or cheap" was non-negotiable. It was expected that pushing for faster releases meant that something in quality would give way. Tightening quality controls meant the schedule slipped. Every engineering leader I know has lived some version of that tradeoff ... The seesaw is starting to level out ...

I have been building enterprise software for more than 20 years ... One thing stays true across all of it: You do not find out your foundation is wrong during the crisis. You find out when the debt comes due. For a lot of organizations, that bill is arriving now. New research ... puts hard numbers on something practitioners have been sensing for a while. The telemetry problem isn't coming. It's already here ...

The rapid growth of AI workloads is pushing traditional log management approaches to their limits, according to The State of Log Management 2026 report from Dynatrace. Modern logs have become critical to understanding, validating, and securing AI-driven decisions, helping organizations ensure reliability, compliance, and performance at scale. However, the volume and complexity of AI telemetry are overwhelming legacy tools ...

For years, secure connectivity has relied on a familiar pattern: route traffic back to centralized gateways, inspect it, and then allow access. This model worked when applications lived in a handful of data centers and users were largely confined to offices. That model is now under strain. Applications are distributed across clouds, users connect from everywhere, and real-time workloads demand performance that centralized inspection points struggle to deliver. As traffic volumes grow and latency expectations shrink, routing everything through a small number of control points has become both a performance bottleneck and a resilience risk. The future of secure connectivity requires a different approach ...

The AI experimentation phase is over, and the private cloud is where enterprise AI workloads are being deployed for security and scale, according to Private Cloud Outlook 2026, a new report from Broadcom ... 2026 marks an acceleration into a full AI tipping point. The shift is being shaped by three forces — costs, complexity, and control — that public cloud environments are increasingly failing to address for production AI at scale. Key findings from the report include ...

44% of organizations have reported an outage in the past year tied to suppressed or ignored alerts, and 78% had at least one incident where no alert was fired at all ... Engineers learned about failures from customers. That gap between what our tools report and what our customers experience is the problem DevOps teams have been quietly solving with GenAI tooling, even as most enterprises continue to run their NOCs on manual alert triage ...

Cloud outages are usually described as technical failures. When a service goes down, a dependency breaks, or a region has issues, the focus immediately shifts to infrastructure. But if you look closely at how these incidents actually unfold, the root cause is rarely the technology itself. It is almost always tied to decisions made earlier, during design, implementation, or day-to-day operations. The system behaves the way it was built. The real question is how it was built ...

77% of leaders say their teams need AI skills urgently. 64% say their organization plans to train current employees rather than hire new ones. So far, so reasonable. The part that surprised me is who's been put in charge: 34% of those leaders say IT and engineering own the AI skills mandate. Learning and Development or HR own it at 7% of organizations. That's roughly five-to-one in favor of the people who understand the tools, over the people whose actual job is teaching adults how to learn new ones ...

In the ever-evolving digital landscape, enterprises are increasingly focused on enhancing their observability stacks to gain deeper insights into their IT environments. Observability has become a cornerstone of modern IT operations, enabling organizations to monitor, diagnose, and optimize their systems with unprecedented precision. However, a critical piece of the puzzle often goes unnoticed in this transformation: IBM i ...