What is astexplorer?

AST explorer is a web-based tool that lets you see how code gets broken down into its internal structure. When you write code, parsers turn it into an Abstract Syntax Tree (AST), essentially a detailed map of what the code means. This tool visualizes that map in real time, making it easy to understand how different parsers interpret your code. Here's how it works: you paste or drag code into the editor, pick which parser you want to use, and the tool instantly shows you the AST on the right side. You can click on parts of the tree to see which lines of code they correspond to, and hover over code to highlight the matching tree nodes. It supports an impressive range of languages and parsing tools, JavaScript (with variants like TypeScript, Flow, and JSX), CSS, GraphQL, HTML, Markdown, PHP, SQL, and more. You can also try different parser options to see how they interpret the same code differently. The tool is particularly useful for developers who are building code transformation tools or linters. If you're creating a custom Babel plugin, ESLint rule, or PostCSS transformer, AST explorer lets you prototype and test your ideas. You can even write transformations directly in the tool and see the results update live. Beyond that, anyone curious about how code works under the hood, or debugging why a parser behaves unexpectedly, will find this helpful. The project is also designed to be extended. The README includes clear instructions for adding new parsers or transformers, making it a collaborative tool that the community can improve. You can save and share code snippets by URL, making it easy to collaborate with others or bookmark examples for reference.