Web sustainability

Web traffic constitutes a significant fraction of all internet traffic. If we are to decarbonize the internet as it exists today, web sustainability is key. Thankfully the W3C has draft guidelines for web sustainability. After reviewing these in February 2025, I thought I'd share my initial reactions and observations.

But first, what is sustainability? One convenient shorthand for sustainability is the ponzi scheme. If the system that you are considering in some way resembles a ponzi scheme then it is not sustainable. And if it in no way resembles a ponzi scheme, it probably is sustainable. I think the goal of the WSG should in essence be to empower people to avoid building ponzi-scheme-like things out of their web applications.

So I think we can thank the W3C for trying to keep us all from turning our websites into literal or metaphorical ponzi schemes. Overall, it is quite welcome to have these guidelines. With guidance on UI design, software architecture, development methods, and business practices, there are many helpful tips to be found in them. For web developers it is worth review and consideration. And many of the detailed rules are labeled as "machine testable", with some guidance provided on how that testing could be performed. How great is that?

Recommendations

The status of the guidelines is "draft". I do see some room for improvement and I am sharing my recommendations here in case the authors might be able to incorporate some of them. If anyone on the project finds any of the following recommendations of interest, I'd be happy to work with them on incorporating them into the guidelines.

• Make the text easier to read. The style of the guidelines can be casual and verbose or in some places too concise. If thousands of developers will read this document it is worth editing it for clarity.
• Improved structure. The guidelines read like a long, flat, list. This makes it hard for readers to find the rules that matter to them most. In other disciplines, like information security, long lists of guidelines can sometimes result in a "checkbox" approach to compliance. Giving more structure to the rules will encourage more thoughtful and effective implementations. It will also make the guidelines more scalable, allowing rules to be added over time effectively.
• Merge similar rules. There are a number of rules that are very similar. For better readability they should be merged. Rules with a large number of subrules are better than lots of very similar rules cluttering up the list.
• Label every subrule as "development", "server", or "client" to indicate the functional/physical components impacted by the rule.
• Every rule must cite a trusted (academic) source of evidence. To be effective and trusted, guidance must be evidence-based. When reading any rule, a natural reaction is "why is this necessary?" A citation is an easy, concise, and compelling answer to this question. If this requirement means removing rules that can't be justified, that's a good thing!
• More information is needed on a variety of topics including the efficiency of different approaches to information security, compression vs. minification, encryption, HTTP/3, server-side frameworks, asynchronous processing, operating systems, and content.

Recommended structure

Here's a sketch of a new structure/taxonomy for the rules. This structure aligns with standard terminology for sustainability. It also blends in a resource-based aspect, since sustainability is fundamentally about resource use.

• Environmental
  • Climate change
    • Mitigation
      • Energy sourcing
    • Adaptation
      • Energy efficiency¹
      • Other resource efficiency
  • Other Environmental
• Social
  • Health
  • Political
• Economic
  • Business model
  • Labor model

Further rationale

At this point it may be clear that sustainability encompasses many, sometimes contradictory, things. Most web developers will care about some of those things and not others. The WSG rules should be organized in such a way that readers can easily focus in on the rules that are valuable for them. Personally I am most interested in CO2E mitigation, and to a lesser extent energy efficiency. For me, while I understand why rules like "Respect the Visitor's Attention" are there, I am finding myself wading through these rules to find the ones that relate to CO2E mitigation. Moving that rule to a category like "Social>Health", for example, would make the guidelines much more usable.

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1) Energy efficiency is listed under adaptation and not mitigation since, due to Jevon's paradox, making a system more efficient does not necessarily reduce its footprint.