When we talk about optimizing content management systems (CMS), performance often takes center stage - and rightly so. Faster load times, improved responsiveness, and streamlined user experiences are essential. But here’s something we don’t talk about enough: performance is a sustainability issue, too.
Every byte delivered over the internet, every uncached page, and every oversized image has an energy cost. Multiply that by the billions of pages served every day, and the environmental impact becomes clear.
At Umbraco, we’re focused on building user-friendly and flexible software, while continuously working to improve our practices in a responsible way. That’s why I want to share five practical ways you can make your CMS - Umbraco or otherwise - leaner, faster, and yes, greener.
Images and videos are some of the biggest performance and energy culprits on modern websites. The good news is that they're also among the easiest to optimize.
Use modern formats like WebP or AVIF.
Enable lazy loading so images only load when visible on screen.
Leverage Umbraco’s ImageSharp or ImageProcessor to automatically serve images in the right size
Result: Faster pages, lower bandwidth, and reduced energy use for end-users and servers alike.
Every time a CMS dynamically builds a page from scratch, it consumes resources. That adds up fast, especially for high-traffic sites.
Use output caching and partial view caching in Umbraco.
Consider server-level caching or reverse proxies like Cloudflare CDN.
Ensure as many of your assets are cached too
Tip: Think of caching not just as a speed trick, but as a power-saving mechanism.
Reducing the number and size of HTTP requests is critical for performance, and it lowers the energy cost of loading your site.
Minify CSS, JS, and HTML.
Use bundling in .NET or a modern build tool like Webpack or Vite.
Enable GZIP or Brotli compression.
Fewer bytes = less work for servers and browsers, and quicker delivery to users.
Many sites start with feature-rich templates or starter kits - but these can become bloated fast.
Build or customize a lean theme that avoids unnecessary scripts, fonts, or UI components.
Audit your views for recursive or inefficient logic.
Remove plugins or packages that aren't actively used.
Performance starts with smart design decisions. Simpler markup and fewer dependencies mean less code to render and maintain.
Where your CMS lives matters just as much as how it runs.
Choose green infrastructure — for example, Umbraco Cloud, hosted on Microsoft Azure, which has a strong sustainability track record.
Use auto-scaling to handle traffic spikes without over-provisioning resources.
Monitor your site with application insights or tools like Lighthouse to improve continuously.
Efficient hosting reduces energy waste and contributes to a smaller digital carbon footprint.
Optimizing your CMS for performance isn’t just a tech task — it’s an opportunity to align your digital presence with sustainability goals. As developers, designers, and digital leaders, we have the tools and responsibility to reduce digital waste.
By embracing small but impactful changes, we can make our web projects faster, more maintainable, and better for the planet.
Let’s build a better web. Together.
Lasse Fredslund is the Product Owner of Umbraco CMS and a dedicated advocate for sustainable software practices. He’s passionate about making web development smarter, simpler, and more environmentally conscious. Reach out to Lasse on lfr@umbraco.dk for help and inspiration on how to get started with optimizing your CMS performance.
