Overview
OpenLitterMap is a free citizen-science app that lets anyone photograph and tag pieces of litter to build a public, open map of plastic pollution. Volunteers worldwide add geotagged photos that record where, when, and what was littered — down to the brand printed on the wrapper. The data is published openly so researchers, councils, and educators can study pollution patterns and act on them.
The project was founded in Ireland in 2017 by geographer Seán Lynch and is recognised by the Digital Public Goods Alliance as a tool aligned with the United Nations Sustainable Development Goals1. It rewards verified contributors with Littercoin, a token issued on the Cardano blockchain — an idea introduced in the project's peer-reviewed launch paper as a way to apply blockchain incentives to producing open environmental data2. OpenLitterMap sits in the impact corner of the Cardano ecosystem and is part of the Cardano4Climate working group.
Key Features
- Public map of every reported piece of litter. Every verified upload appears as a point on a global, browsable map, alongside live notifications of new submissions from around the world3.
- Photos tagged down to the brand. Contributors don't just log "plastic bottle" — they record the object, material, and brand visible on the packaging, so the dataset can show which companies' products turn up most often in the environment.
- Cardano-based contributor reward. Verified data producers earn Littercoin, an open-data reward token that migrated from Ethereum to Cardano in 2021 with a Project Catalyst community grant4. The token is intended for community use rather than exchange trading.
- Recognised Digital Public Good. OpenLitterMap is listed in the official Digital Public Goods Alliance registry, a UN-endorsed catalogue of open-source tools that advance the Sustainable Development Goals1.
- Open code, peer-reviewed origins. The full platform is open source on GitHub under a GPL-3.0 licence, and the original concept was published as a peer-reviewed paper in Open Geospatial Data, Software and Standards2. The dataset has since been cited in dozens of academic studies5.
What to Expect
When you visit the site, the homepage shows a live feed of new uploads streaming in from around the world. You can open the global map and zoom into any country, city, or street to see what people have logged — useful both for getting a sense of the project and for finding hotspots near you. There is also a leaderboard, country-by-country location pages, and a public reference list of academic papers that have used the data.
To contribute, you sign up for a free account, install the mobile app or use the web uploader, and start adding photos. New users are anonymous by default and have their first submissions reviewed by a small admin team before going public; trusted users have their uploads verified through a community process3. Tagging is straightforward — pick from a library of pre-defined object, material, and brand tags, or add your own — and most volunteers can map their first piece of litter within a few minutes of signing up. The platform supports several languages and works on phones, tablets, and laptops.
If you mainly want to use the data, downloads and references live on the site itself; if you want to contribute code or follow development, the work happens openly on GitHub and Project Catalyst.
