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Web Performance and the Impact of SPDY, HTTP/2 & QUIC - Part 1

Jean Tunis

As websites continue to advance, the underlying protocols that they run on top of must change in order to meet the demands of user expected page load times. This blog is the first in a 5-part series on APMdigest where I will discuss web application performance and how new protocols like SPDY, HTTP/2, and QUIC will hopefully improve it so we can have happy website users.

Start with Web Performance 101: The Bandwidth Myth

Start with Web Performance 101: 4 Recommendations to Improve Web Performance

So How Are We Doing?

In my last blog, I talked about all the different recommendations I've provided or come across over the years.

How are we doing with that? Are website owners out there listening?

Well, I decided to take a look at the archive — HTTP Archive, that is.

With HTTP Archive, I can look at some worldwide statistics on thousands of websites it monitors.

Let's look at bytes being sent to the browser.


As we can see, the average total byte size of a web page is a little over 2.3MB. And look at the biggest percentage in type of files: images account for about 63% of worldwide page sizes. Those file sizes can be reduced or minimized.

Okay. So maybe that was an outlier. In Performance Engineering, we never want to focus too much on averages. Percentiles and trends are things that give us better insight into whether something should be a concern or not.

So let's look at the trend in the past year.


We see that the trend of transfer sizes has been going up in the past year. Websites across the world have increased in size by about 18%. At this rate, if it continues, in 5 years, websites will increase in size by almost 300%! That's crazy!

While I think this is unlikely to happen with the increased importance placed on web performance, it's unbelievable to think we're increasing at this rate.

In my last blog, I mentioned how important it is to reduce latency. One of the ways to do that is to implement a content delivery network.

So let's see how that's going across the world.


We can see that only about 14% of websites have implemented a Content Delivery Network (CDN). With free CDNs out there, everyone should be using a CDN.

It's also encouraging that we're trending upward on that one.

Now that we get a sense of how websites are doing with HTTP requests across the globe, I want to look at the the protocol itself. If website operators are only slowly making some improvements, what can be done with the protocol itself to help?

Read Web Performance and the Impact of SPDY, HTTP/2 & QUIC - Part 2, covering the limitations of HTTP/1.0 and HTTP/1.1.

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Web Performance and the Impact of SPDY, HTTP/2 & QUIC - Part 1

Jean Tunis

As websites continue to advance, the underlying protocols that they run on top of must change in order to meet the demands of user expected page load times. This blog is the first in a 5-part series on APMdigest where I will discuss web application performance and how new protocols like SPDY, HTTP/2, and QUIC will hopefully improve it so we can have happy website users.

Start with Web Performance 101: The Bandwidth Myth

Start with Web Performance 101: 4 Recommendations to Improve Web Performance

So How Are We Doing?

In my last blog, I talked about all the different recommendations I've provided or come across over the years.

How are we doing with that? Are website owners out there listening?

Well, I decided to take a look at the archive — HTTP Archive, that is.

With HTTP Archive, I can look at some worldwide statistics on thousands of websites it monitors.

Let's look at bytes being sent to the browser.


As we can see, the average total byte size of a web page is a little over 2.3MB. And look at the biggest percentage in type of files: images account for about 63% of worldwide page sizes. Those file sizes can be reduced or minimized.

Okay. So maybe that was an outlier. In Performance Engineering, we never want to focus too much on averages. Percentiles and trends are things that give us better insight into whether something should be a concern or not.

So let's look at the trend in the past year.


We see that the trend of transfer sizes has been going up in the past year. Websites across the world have increased in size by about 18%. At this rate, if it continues, in 5 years, websites will increase in size by almost 300%! That's crazy!

While I think this is unlikely to happen with the increased importance placed on web performance, it's unbelievable to think we're increasing at this rate.

In my last blog, I mentioned how important it is to reduce latency. One of the ways to do that is to implement a content delivery network.

So let's see how that's going across the world.


We can see that only about 14% of websites have implemented a Content Delivery Network (CDN). With free CDNs out there, everyone should be using a CDN.

It's also encouraging that we're trending upward on that one.

Now that we get a sense of how websites are doing with HTTP requests across the globe, I want to look at the the protocol itself. If website operators are only slowly making some improvements, what can be done with the protocol itself to help?

Read Web Performance and the Impact of SPDY, HTTP/2 & QUIC - Part 2, covering the limitations of HTTP/1.0 and HTTP/1.1.

Hot Topics

The Latest

The enterprises that will define the next decade are not the ones that deployed the most technology. They are the ones who understood what their technology was actually doing. That distinction is not a philosophical point. It is the central operational challenge facing every organization that has spent the last five years modernizing at speed ...

AI is becoming the operating system of the enterprise. It acts as an invisible coordination layer that understands intent, connects systems, and executes work across complex SaaS environments. Previously, employees had to click through multiple systems — CRM, ERP, support tools, collaboration platforms — to complete a single task. Now, instead of navigating each application manually, they can simply state what they need to accomplish ...

In 2026, the cost of downtime or an outage is no longer just a technical inconvenience; it's a $600 billion wake up call for global businesses. As our digital ecosystems become  more interconnected, each touchpoint introduces new risks and multiplies the consequences when things go wrong. And the data is clear: aggregate downtime costs  for Global 2,000 companies have surged 50% since 2024, reaching a staggering $600 billion ...

Deloitte found that 74% of enterprises expect to deploy agentic AI solutions in the next 24 months. However, the rush to deployment is outpacing foundational work, though. Only 21% of enterprises have fully formed agent governance models in place. The result? AI agents deployed without guidance or governance begin to function as fragmented islands of complexity ...

Cloud spending is no longer viewed as a passthrough IT expense, but as a strategic financial lever that directly impacts innovation capacity, profitability and enterprise resilience, according to the CFO Cloud Cost Optimization Report from Azul ...

As AI moves from generating responses to performing actions, the need for trust increases exponentially. And as organizations enlist AI agents for increasingly sophisticated business processes, trust is going to be the single most important theme for spurring adoption. What can organizations do to build trustworthy AI agents? ...

I've spent a lot of time in the channel, and one thing I keep coming back to is this: a partner program is only as good as what it looks like in the field. Many programs look great on paper, but when a partner is in front of a customer navigating a complex hybrid environment or trying to make the case for AI-powered observability, the gap between what a vendor promises and what it actually delivers becomes very clear, very fast ...

Enterprises today operate in a real-time environment where uninterrupted access to trusted data has become a baseline expectation for users, applications and automated systems. Traditional DataOps models, built on manual effort and human triage, cannot keep pace with this always active demand. AI agents are emerging as the operational backbone, ensuring consistent data availability, reinforcing trustworthiness and enabling a level of scale that manual processes cannot achieve ...

For decades, trust in the digital workplace rested on familiar signals. We trusted faces on video calls, voices on the phone, and emails that appeared to come from people we knew. These cues felt human and intuitive. They anchored how decisions were made, approvals were granted, and access was authorized. AI-powered deepfakes have quietly broken that model ...

Cloud migration was supposed to be a one-way door. For most enterprises, it turns out it isn't. Cloud data repatriation is a real and growing trend. A new survey ... finds that 89% of organizations plan to expand their on-premises infrastructure footprint over the next two years — and 75% have already moved at least some workloads back from public cloud in the past 24 months. The findings point to a broad rethinking of where data belongs ...