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WSG Overview

https://www.w3.org/TR/web-sustainability-guidelines/

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Tzviya Siegman, Alex Dawson, Tim Frick, Ines Akrap, Mike Gifford

November 2025

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What we’ll cover today:

WSG

  • Context: Why these guidelines?
  • Web Sustainability Guidelines (WSG) Overview

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  • Supplemental documents
  • Implementations
  • Feedback

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The web represents 2-5% of global annual emissions (and rising).

Full width image

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Sustainability: Three Pillars

E

S

G

Environment

Address the Internet’s environmental impact

Social

Improve social impact of digital products & services

Governance

Employ responsible economic practices for tech projects

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WSG: Starting Goals

Make it easier for anyone to apply sustainability principles to digital products and services they create or manage.

Measurably improve the internet’s environmental, social, and economic impact.

Align efforts with existing environmental, social, and economic reporting standards (GRI).

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Business & Product Strategy

Business & Product Strategy: �

Guidelines aimed at organizational and team leaders to help them make more informed strategic and operational decisions.

Examples:

  • Estimate the environmental impact
  • Plan for a digital product or service's care and end-of-life

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Examples of Business & Product Strategy

5.9 Support mandatory disclosures and reporting

Create policies and documents showing evidence of commitment towards impact progress, how this is achieved, and any applicable regulations you are meeting.

Success Criteria

  • Policies and practices
  • Impact report
  • Impact reduction

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Web Development:

�Guidelines to help programming teams improve performance, reduce data payloads, and lower digital emissions.

Examples:

  • Set goals based on performance and energy impact
  • Avoid redundancy and duplication in code
  • Structure metadata for machine readability

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Examples of Web Development Guidelines

3.4 Remove unnecessary code

Success criteria

Clear out dead or unused code as it builds up in a project to reduce the amount of wasted data being transferred.

Remove redundancy

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Hosting & Infra

Hosting & Infrastructure:

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Guidelines to help teams make more informed decisions about third-party technology suppliers and practices.

Examples:

  • Choose a sustainable service provider
  • Optimize caching with offline access supported
  • Data storage strategies
  • Automation efficiency practices

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Examples of Hosting/Infra Guidelines

4.2 Optimize caching with offline access supported

Success criteria

Use caching on all appropriate resources, prioritizing the ability to use the resource offline if possible.

  • Utilize caching
  • Offline access

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UX Design

UX Design:

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Guidelines to improve digital experiences for all users while also helping people make more sustainable choices.

Examples:

  • Understand the impact for non-users
  • Avoid being manipulative or deceptive
  • Evaluate feature use, value, and impact

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Examples of UX Design Guidelines

2.15 Optimize images for sustainability

Success criteria

Ensure images, if required, are optimized, correctly formatted, and sized, with lazy loading as appropriate, and are managed effectively.

  • Need for images
  • Optimized images
  • Lazy loading
  • Sizing and deactivation
  • Image management and use

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Work-in-progress:

  • Collaboration with other standards plus an internal system for prioritization and ranking based on GRI.
  • Continue to improve the machine testability provided in Sustainable Tooling and Reporting (STAR) to increase adoption through tooling.
  • Metrics Discussion

Measurement

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Supplemental documents

Documents that reinforce WSG guidance

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Implementations and Experiments

Tools, website, apps, experiments

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Q&A

Feedback

https://github.com/w3c/sustainableweb-wsg

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