Author:
- Taylore Givens, Program Manager
Proposal for a feature not yet in development. Please share your feedback here.
web app sustainability – energy consumption and type of energy (i.e. fossil fuels/renewable) used for a web app
The carbon impact of the internet, including the hardware, software, and systems that go into creating it, produces about 3.7% of global carbon emissions. This is similar to the percentage of global emissions from the airline industry. Developers and the public are becoming increasingly more aware and concerned about this issue. Developers are increasingly interested in understanding what factors impact a web app's sustainability and how to improve it's sustainability. Consequently, tools such as Website Carbon, Ecograder, EcoPing, and Beacon have been created to calculate the amount of CO2 a web app emits and provide recommendations to improve the sustainability of a web app.
Adding sustainability features to DevTools will raise awareness about the alarming carbon impact of web apps and the internet and help developers measure and improve the sustainability of their web apps by
- Providing proxy web app sustainability measurements
- Highlighting common factors that reduce the sustainability of web apps by showing or explaining how these factors decrease performance and increase energy consumption
- Indicating to developers what actions they’re currently taking, such as performance improvements, that also improve web app sustainability
- Educating developers on new actions they can take that are purely beneficial for sustainability.
- Label existing issues in the Issues panel that are beneficial to sustainability and energy efficiency
- Create a “Sustainability” tab that is a hub for sustainability-related metrics and provides insights about web app energy consumption, the type of energy used to power a web app, third parties' impact on performance and energy, and best practices to improve sustainability.
Mockup is conceptual, not the final design
Once the user navigates to the Issues panel, any issue or category relevant to improving sustainability will have a sustainability label. Clicking this label will expand the category or issue dropdown window. The dropdown window will include a green banner describing how the category or issue is related to sustainability. The banner will also include a link to external documentation to learn more about why the category or issue is sustainability related. The banner will potentially also include a link to the DevTools Sustainability Tab (see next section).
Sustainability labeling will be enabled by default but can be disabled with the checkbox to reduce noisiness. Categories or issues labeled as sustainable would be prioritized in the ordering of categories and issues.
This tab will be a hub for sustainability-related metrics and provide insights about web app energy consumption, the type of energy used to power a web app, third parties' impact on performance and energy, and best practices to improve sustainability.
Although developers requested a web app carbon calculator feature in DevTools, like Website Carbon, these types of algorithms are underdeveloped and inaccurate because they often rely on inputting the byte size of a website and applying average ratios (i.e. kWh/byte and CO2 g/kWh) to get a carbon estimate. This type of algorithm is better suited to estimate the carbon emitted from the energy used to transfer a web app over the network rather than estimate the total carbon emissions associated with a web app.
The Sustainability tab has three sections: Sustainability Analysis, Third Party Impact, and Best Practices.
Sustainability Analysis
Energy Consumption
The Client-Device Energy and Network Transfer Energy sub-sections display proxy metrics relevant to how much energy is used to render the web app on the client device and transfer it over the network to give the developer a sense of the energy consumed by the web app.
Client-Device Energy
- “Client-Device Energy Score“ is out of 100 and is based on the CPU utilization and GPU utilization of the web app's initialization compared to the average web app. The score will vary slightly depending on the client's device due to different hardware. The score should be used as a guideline metric to assess how incremental code changes affect the client device energy.
- CPU metrics such as the average CPU utilization and the live CPU utilization
- Link to Performance tab to further investigate CPU utilization
Network Transfer Energy
- Bytes transferred and number of network requests to give context to the amount of network activity the web app is generating
- Use an open-source API, such as the Green Web Foundation API, to get a carbon estimate and display this value as the emissions from the energy required to transfer the web app bytes over the network.
Energy Type
Display whether the web app runs on a green hosting service (i.e. service that runs on renewable energy) based on the Green Web Foundation's open source dataset.
Third-Party Impact
Third parties are often incorporated or added on top of web apps without much thought as to how they affect the weight and performance of the app. We will display the following data to help developers identify the potential negative impact third parties are having on their web app.
- number of requests made to third parties
- number of bytes transferred from these network requests/all bytes transferred
- time consumed by third-party requests/total load time for web app
Best Practices
Sustainable web app design recommendations focus on making the web app as light and high-performant as possible by limiting unnecessary web app components.
There are certain properties we recommend eliminating or adding to a web app to improve its sustainability, such as eliminating inline CSS Styles because inline CSS can’t be cached or minifying all your CSS and Javascript.
However, for other properties that negatively impact sustainability, it's unreasonable to recommend that all web apps eliminate these properties such as custom fonts or large photos. Therefore, we will provide a table that shows the number of custom fonts, large photos, and other properties in a color-coded manner to indicate which counts are above or below average to give developers a sense of how sustainable their website is compared to other sites.
We welcome community feedback on this concept and the content proposed.