Thoughs and records on IoT, Web Sites and Microprocessors.

Size (still) Matters on the Web

Web application size optimization visualization comparing 1990s to 2025

The size of web applications remains a critical factor affecting user experience, performance, SEO, and business success. Developers must carefully consider application size to ensure optimal performance and user satisfaction.

The size of web applications is crucial for several reasons:

User Experience: Smaller web applications are easier to navigate and use, especially on mobile devices.
Performance: Smaller applications load faster, which is particularly important for mobile users who may be on slow or unreliable connections.
SEO: Mobile-friendly applications are more likely to rank well in search engine results, as they provide a better user experience.
Business Success: Responsive web design can significantly impact conversion rates, as users who have a positive experience are more likely to make purchases or engage with content.

From the 1990s to 2025: A Size Comparison

In the 1990s, network payload size was a major concern due to limited connectivity through leased lines (1-44 Mbps) and dial-up modems (2.4-56 Kbps).

While today’s access speeds are significantly faster (1-20 Gbps to end users), the importance of size optimization hasn’t diminished. Instead, both customer demands and performance metrics have evolved considerably.

1990s Traffic Footprint

Email: ~20KB (text only)
Webpage: ~14KB (basic styling only)
Image: ~30KB (exceptional)

Users were accustomed to waiting for transfers to complete. Network latency primarily affected DNS lookups.

2025s Traffic footprint

Video streaming: 15-20GB (even 4k video)
Cloud sync: 2-5GB
Social media: 1-2GB (often replacing Email)

Modern web pages combine multiple resource types:

HTML: ~50KB
JavaScript: ~500KB-2MB
CSS: ~200KB
Assets/Images/video: 1-5MB

Today’s network latency includes secure connection initialization and multiple DNS lookups per page. These overhead costs can be minimized through resource bundling, HTTP/3, and Edge Network implementations.

Modern Performance Metrics

Current standards consider load times under 2 seconds as “good,” with up to 5 seconds being acceptable for mobile devices.

Core Web Vitals focus on end-user experience metrics:

First Contentful Paint (FCP): 1.8 seconds
Largest Contentful Paint (LCP): 2.5 seconds
Time to Interactive (TTI): 3.5 seconds

These metrics encompass not just download times but also rendering performance and JavaScript functionality.

While network payload remains important, developers can leverage:

Lazy loading for images
Deferred loading of non-critical JavaScript
Local caching for returning users

Size optimization remains crucial because:

Large downloads can severely impact usability on low-bandwidth connections
Network traffic often directly affects hosting costs
IoT devices have limited storage capacity

Modern Web Application Architecture

But still size is the main factor to be worked on.

While the repeated download of the same html was part of the 1990s applications as data was transferred to the client side together with the formatting tags and attributes by the frameworks at this time.

The AJAX was introduced at the end of 1990s.

Today’s web applications benefit from improved architecture patterns:

Static content (HTML, CSS, JavaScript, and assets) can be optimized through pre-deployment minification
Dynamic data is served via RESTful APIs, delivering only essential JSON data
Client-side applications can implement sophisticated caching strategies using local storage
Progressive loading enables better user experiences

Key optimization strategies include:

Minification of HTML, CSS, and JavaScript
Leveraging native browser functionality instead of legacy libraries
Implementing effective caching strategies
Smart resource bundling
Image optimization
Consolidated server requests

When using the current frameworks for web applications there is a strict split between

static data (HTML, CSS, JavaScript and Assets) that can be minimized by static code analysis before deployment and
application data, typically JSON data provided by restful services that ONLY contains data.

This split is key to optimize application experience after initial loading and applications running in the browsers can implement local caching strategies using local storage and can incrementally load more when required for user
interaction.

(This applies to mobile applications as well).

The size of HTML, CSS and JavaScript can be reduced before publishing by using minification
Prefer using the current built-in native functionality instead of using old libraries.
Implement local caching strategies.
Intelligent bundling
Image formats can be optimized.
Loading from multiple servers can be avoided.

And Beyond…

There are situations beyond the above situations with limitations:

Implementing UI for user remote access to IoT devices.

Here the devices need to host a web server, store the static files and provide services for the functionality.
Implementing for low bandwith networks.

Conclusion

Size optimization remains a critical factor in web development. Organizations and engineers should:

Implement regular size monitoring in CI/CD pipelines to get early indicators when size changes.
Maintaining focus on application size helps ensure optimal performance, user satisfaction, and business success.
Apply optimization techniques during development
Include size optimization in deployment processes