Slack made communication effortless. It also made it one of the most carbon-heavy messaging apps out there.
So I designed Green Mode, a feature that makes digital waste visible, with Greenbot to help clean it up.
problem
Slack serves as the global headquarters for 47+ million daily users. With 1.5 billion messages sent every single day, it is the most successful collaboration tool in history, because it made communication effortless.
So what’s the catch?
DemandSage / ElectroIQ (2025 reports).
research
A 2024 comparative audit analyzed the environmental impact of a standard “user journey” (sending text, images, and GIFs) across major platforms.
Carbon cost per journey
The report classifies business tools like Slack as suffering from digital obesity: bloated software that consumes excess energy to maintain features (like infinite history) that users rarely utilize.
“Environmental Impact of Messaging Apps,” Greenspector Audit (2024).
Slack feels like a temporary stream, but it acts like a permanent vault. Users mistakenly treat messages like throwaway comments.
“It often feels like a dumping ground.” – Reddit user (r/projectmanagement), Jan 2025
How might we make storage feel tangible, not abstract?
Slack’s primary upsell is “Unlimited Message History,” financially incentivizing companies to never delete a single byte.
“If you don’t pay, there is no way for you to see a conversation ever again… It’s brilliant…” – Satya van Heummen, tech product analyst
How might we turn deletion into a shared goal instead of a chore?
Due to the app’s complex nesting structure, users find it difficult to relocate, and consequently, delete old files.
“Conversations are unstructured, so important answers are hard to find again.” – Verified user review, eesel.ai blog, Aug 2025
How might we make digital waste visible?
I began by drawing out the site map by hand, followed by a digital recreation. I found several points in the system resulting in hidden waste: confusing channel structure, hidden documents, difficulty marking as ‘read’.
Old vs new site map – hover the blinking points to see where the new feature steps in.
design
Narrowing the problems down to hidden waste, I started visualizing how to make chat waste feel tangible and visible.
I came up with ‘weight’ icons on each chat, showing how ‘heavy’ its waste is.
Rough ideas – weight icons on each chat.
During my sketching, I was trying to visualise a space where all the ‘green’ habits could live together.
I decided to start taking inspiration from Slackbot, Slack’s already-present AI assistant. Maybe something similar could keep track of eco-friendly habits?
Rough ideas – the sketched Greenbot.
The character illustration borrows from Slack’s already-present AI assistant, maintaining brand guidelines and user trust.
The design is not simply ‘green,’ but takes inspiration from leaves to incorporate the true eco-friendly feel.
Animations and motion ensure Greenbot feels friendly, approachable, and intuitive.
Repeated use of the leaves to indicate levels of waste
Channels ›
Looks like you have unused data.Get rid of the waste.
Ensuring Greenbot is used throughout the feature, not just on the dashboard
Progress bar to build motivation
Carbon Credit
You are currently 6 GB away from this month’s discount 😀
4 GB of 10 GB deleted
business incentiveA discount is offered to company workspaces that delete 10 GB of data within an allocated time period!
solution
Green Mode on: each channel’s ‘weight’ shows as a leaf.
Tapping a leaf: Greenbot offers to clean up, or send files to Drive.
Greenbot lives in the apps section.
Greenbot’s dashboard: carbon credit and recommendations.
Once Green Mode is on, users can identify which channels hold the most waste. The feature will then point them to discard it, either within the app or through a transfer.
Through Greenbot, there is also an ever-present dashboard where users can keep track of all their green habits.
