# fkling/astexplorer

A web tool to explore the ASTs generated by various parsers.

Repository: https://github.com/fkling/astexplorer
Canonical: https://ross.abutalabs.com/products/astexplorer
Homepage: https://astexplorer.net/
Language: JavaScript
License: MIT
License Family: permissive
Topics: ast-explorer, parser, ast, jscodeshift, babel, postcss, javascript
Last push: 2024-04-26T13:48:46+00:00

## Health v2 (maintenance only)
Score: 23/100 (v2, computed 2026-09-02T17:46:02.011165+00:00)
- activity 0, release rhythm 8, longevity 100
- inputs: {"age_days": 4447, "days_push": 859, "days_rel": null, "gap_med": null, "n_releases_24m": 0}
- flags: none
- formula: round(0.45*activity + 0.35*rhythm + 0.20*longevity); archived -> min(score, 10)

## Adoption (not part of the score)
Stars 6542, forks 773 (observed 2026-08-28T04:09:45.068654+00:00)

## What it is
A web-based tool for exploring the abstract syntax trees (ASTs) generated by dozens of parsers for JavaScript, CSS, HTML, GraphQL, YAML, and more. It also lets developers prototype AST transforms with tools like Babel, ESLint, and jscodeshift directly in the browser.

## Use cases
- inspect the AST of a JavaScript snippet
- compare output of different parsers like babel, acorn, and typescript
- prototype a babel plugin transform
- write and test a jscodeshift codemod
- explore the AST of CSS or HTML code
- debug eslint rule development by viewing the parsed tree
- learn how code is represented as syntax trees

## When to choose
- you are developing or debugging AST-based tools like babel plugins, eslint rules, or codemods
- you want to quickly inspect how a parser represents code without setting up a project
- you need to compare AST output across many parsers and languages in one place

## When to avoid
- you need AST parsing as a library inside your own application - use the individual parsers directly
- you need offline or programmatic AST analysis at scale
- you need parsers for languages not listed among its supported set

## Facets
- artifact type: application
- maturity: active
- function: parser, developer-tools, editor, web-scraping
- domain: developer-tools, parsers, web-development, programming-languages
- platform: browser
- tags: ast, ast-explorer, code-parsing, babel, jscodeshift, codemirror, online-tool, web-server, javascript, nodejs

## Member repositories
- fkling/astexplorer (main) score 23

## Provenance
- Observed fields: from GitHub, fetched 2026-08-28T04:09:45.068654+00:00.
- Health v2: computed from the inputs above; adoption is never an input.
- Inferred fields (summary, facets, guidance): AI-extracted, prompt v1, taxonomy v1, on 2026-08-29T17:44:06.610232+00:00, confidence not recorded.
  - readme: https://github.com/fkling/astexplorer (fetched 2026-08-28T04:09:45.068654+00:00, sha 68fe1c87992a)
  - homepage: https://astexplorer.net/ (fetched 2026-08-29T08:40:38.443932+00:00, sha eb11b5f5560a)
- Data as of 2026-08-30T08:39:29.467469+00:00.