This is an open-source downloadable tool that has been developed with community-led citizen science projects in mind. The Data Postcard tool is designed for community members and citizen science practitioners wanting to share the data they collect. It is a creative way to visualise and share data from a citizen science project. It can illustrate something simple, like the amount of times you walk through an area with high air pollution over the course of a week, or the kinds and amounts of animals you have observed in a prescribed area. This tool is designed for participants in a citizen science project once data have been collected; no previous experience of data visualisation is required.This page includes a Data Postcard guidance document which outlines the tool, the steps, resources needed and useful links that can explain the process of using the tool yourself. The page also includes a Data Postcard download, which can be used in conducting the activity.