JavaScript AST Parser

Paste JavaScript code to break it down into readable components — with a field-by-field breakdown and, where relevant, its structure tree. Everything is processed on your device.

or press Ctrl+Enter
Result
Fill the input and click Parse — the structured result appears here.

Everything runs in your browser. Your data is never sent to our servers.

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Example

Example Input

const add = (a, b) => a + b;

Example Output

AST tree + node counts

How to Use

  1. 1Paste the JavaScript code you want to parse into the input box.
  2. 2If the tool asks for an extra field (e.g. a JSON Pointer or JSONPath), fill it too.
  3. 3Click Parse (or press Ctrl+Enter).
  4. 4See the component breakdown in the Components tab, the tree structure in the Tree tab (when available), and the normalized JSON in the JSON tab. Click Copy to copy the JSON.

About JavaScript AST Parser

JavaScript AST Parser turns JavaScript code into an Abstract Syntax Tree (AST) — a tree representation of its syntactic structure. You can explore each node (functions, expressions, declarations) and see the count of each node type.

Parsing uses acorn, a fast, standards-compliant ECMAScript parser, loaded on demand. Useful for learning how parsers work, building tools, or analyzing code.

FAQ

Is my data sent to a server?

No. The entire parsing is done in your browser with JavaScript. Nothing is uploaded, logged, or stored on our servers — safe for sensitive data.

How is this parser different from a validator or formatter?

A parser turns raw input into its component structure so you can see its building blocks (and, for code, its AST/DOM tree). A validator only checks valid/invalid, and a formatter just tidies the layout. A parser focuses on "what it contains and how it is structured".

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