Observable

Observable is a collaborative data visualization platform built around reactive JavaScript notebooks, founded by Mike Bostock, the creator of D3.js. The platform runs entirely in the browser, eliminating the need for local development environment setup, and supports literate programming by weaving together Markdown, JavaScript, HTML, and SQL in a single reactive document. Over one million notebooks have been created on the platform since launch. Observable's reactivity model automatically re-runs cells when their dependencies change, so updating a data variable or interacting with an input control immediately propagates changes through all dependent cells, creating a live feedback loop for data exploration. The platform ships with D3, Observable Plot, and Observable Inputs pre-installed, and allows importing any library from npm or cells from other notebooks, enabling code reuse across the community. Database connectivity includes native connectors for Google BigQuery, Snowflake, DuckDB, PostgreSQL, MySQL, and Microsoft SQL Server, with credential management and query result caching built into the notebook environment. Real-time multiplayer editing supports concurrent editing with live cursors, inline comments, automatic version history, and git-style forking and merging for branching exploratory analyses. Notebooks can be embedded in production applications as iframes or imported as reactive JavaScript modules, bridging the gap between prototyping and deployment. Additional features include drag-and-drop file uploads, interactive input widgets like dropdowns, sliders, and checkboxes, a minimap visualization of the reactive dataflow graph, and AI-assisted code completion and error fixing. The platform serves data scientists, journalists, researchers, and engineers at organizations including the Cato Institute and IOP Systems. Notebooks 2.0, launched in 2026, introduced a redesigned editor with improved performance and collaboration features.