Building a Greener Web
Like Duolingo, but for Building a Greener Web. Tomo turns the whole topic into a game you play five minutes a day, until it actually sticks.
For the part of you with thirty open tabs that never became anything.
22 levels across 3 sections, about 44 minutes end to end, roughly 9 days at five minutes a day. It moves through The Impact of Code, Building Lean and Efficient, and Optimizing for the Planet. It starts from scratch.
Free forever · No credit card · iPhone & Android
Key ideas in Building a Greener Web
- Data doesn't move for free; it requires electricity to leave the server, travel through cables/routers, and arrive at the phone
- Page weight is the sum of all images, scripts, and code sent to the browser
- Larger files require more energy to transmit across the network
- Every byte of data has a direct energy cost across the entire internet infrastructure
- Lowering page weight is the most effective way to reduce a site's carbon emissions
- Measuring file size is the standard starting point for digital sustainability
- The user's device CPU must work harder to process messy or heavy code
- OLED screens save energy by turning off pixels for black or very dark colors
- Increased CPU activity consumes more battery power
- The relationship between data transfer and physical energy consumption
- Bright white backgrounds require every pixel to be fully powered
- Frequent charging cycles caused by inefficient sites shorten the physical lifespan of hardware
- The primary metric for measuring a site's environmental impact
- Vibrant, high-brightness colors consume more electricity than muted or dark tones
- The impact of color choice on OLED screen power consumption
- True sustainability starts with reducing the energy needed to run the site (efficiency)
You've tried the other tabs
Thirty open tabs. Four facts you actually kept.
You watched. You nodded. By Sunday it was gone.
One answer, then back to scrolling.
Eight weeks. You meant to finish. You didn't.
Tomo gives Building a Greener Web the Duolingo treatment: levels, streaks, and quick quizzes that test what you just learned. That game loop is what the tabs above never had, so it's the one you actually finish.
Here's what playing it feels like
A real question from this course. Take your best guess.
How does file size generally affect the energy needed for data transfer?
Get it right to open this lesson and 21 more in the app.
Where Building a Greener Web takes you
Learn to build websites that are fast, functional, and kind to the planet. Discover how efficient code and smart design choices can significantly reduce the carbon footprint of the digital world.
- 1
The Impact of Code
- The Carbon Footprint of a Website
- Lean HTML: The Foundation of Low-Energy Sites
- 2
Building Lean and Efficient
- Sustainable CSS: Style without the Weight
- Green JavaScript: Logic that Saves Battery
- Smart Assets: Images and Fonts
- 3
Optimizing for the Planet
- Measuring and Monitoring Impact
- Green Hosting and the Ecosystem
3 sections · 7 units · 22 levels. Built to play, not to enroll.
You pick the voice
Building a Greener Web is taught in the The Professor style: clear, structured, thorough. Want a different feel? In the app you can spin up the same topic in any of Tomo's teaching styles. Same facts, totally different vibe.
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Start Building a Greener Web today.
Download Tomo, search Building a Greener Web, and play your first lesson in under a minute.