Eleventy is a JavaScript-based static site generator designed to transform templates, data files, and markdown into optimized HTML. It functions as a versatile template rendering engine and content management framework, allowing developers to aggregate data from diverse sources—including local files, databases, and external APIs—to populate structured web content.
The project is distinguished by its template-engine-agnostic pipeline, which decouples the build process from specific rendering languages. This allows users to integrate multiple template formats, such as Liquid, Nunjucks, Handlebars, or EJS, within a single project. Its architecture relies on a data cascade that merges global settings, directory-specific configurations, and front matter into a unified context, providing a flexible foundation for complex site structures.
Beyond core generation, the system includes a robust set of automation tools for managing the build lifecycle, including incremental builds, file watching, and programmatic execution. It supports advanced content workflows through features like automated pagination, internationalization, and component-based asset bundling. The platform is highly extensible, enabling users to hook into the build process via plugins to perform custom transformations, image optimization, or syntax highlighting.
The project provides comprehensive documentation and supports configuration through modular files or TypeScript, facilitating consistent environments across different development setups.