Outline a Source File's Functions, Classes & Methods
Paste code in any of 11 languages and get a nested symbol tree — functions, classes, and methods — as text, a Markdown TOC, or JSON. Nothing leaves your browser.
About this tool
Paste a source file and get a nested outline of its functions, classes, and methods — the same "symbol tree" or Outline view your editor shows, but without installing anything. It's a fast way to map an unfamiliar file, build a table of contents for documentation, or prepare a compact structure summary before feeding code to an LLM.
The extractor supports Python, JavaScript, TypeScript, Rust, Go, Java, C, C++, C#, PHP, and Swift. Leave the language on Auto-detect and it guesses from the code (Python by indentation, everything else by brace nesting), or pick a language explicitly if the guess is wrong. Methods nest under their class, and inner functions nest under the function that contains them.
Choose one of three output shapes:
- Indented tree — a plain-text outline, one entry per line, indented by depth.
- Markdown list — a nested bullet list you can paste straight into docs as a table of contents.
- JSON — a nested array of
{kind, name, line, signature, children}for scripting or further processing.
Turn on Show full signatures to display each entry's whole header line (for
example def add(a, b)) instead of just its name, and Show line numbers to
annotate every entry with its source line.
Everything runs locally in your browser via WebAssembly — your code is never uploaded to a server. Because the outline comes from a dependency-free brace-depth / indentation heuristic rather than a full language parser, unusual multi-line signatures or heavily macro-generated code may occasionally be missed; it's built for quick navigation, not compiler-grade accuracy.
FAQ
Which languages does it support?
Python, JavaScript, TypeScript, Rust, Go, Java, C, C++, C#, PHP, and Swift. Leave the Language menu on Auto-detect to let the tool guess, or select one explicitly when the code is ambiguous (for example a short snippet with no language-specific keywords).
Is my code uploaded anywhere?
No. The whole outline is computed in your browser with WebAssembly. Nothing is sent to a server, so it's safe to paste proprietary or unpublished code.
How does it detect functions and classes without a real parser?
It uses a deterministic heuristic instead of a full language parser (those are C
libraries that don't run in the browser sandbox). For brace languages it tracks
bracket depth — ignoring brackets inside strings, character literals, and
comments — and treats keyword declarations (class, struct, fn, function,
def, impl, …) and block-opening name(args) { signatures as symbols. For
Python it uses indentation. This is fast and dependency-free, but unusual
multi-line signatures may be missed.
Why is a method sometimes labelled "function"?
A function is relabelled method only when it sits directly inside a
class-like construct (class, struct, interface, trait, impl, enum). A
standalone function, or one the heuristic couldn't nest under a class, stays
labelled function.
What do the three output formats give me?
Indented tree is a plain-text outline, one symbol per line. Markdown list
is a nested bullet list you can drop into a README as a table of contents. JSON
is a nested array of {kind, name, line, signature, children} objects — the JSON
form always includes the signature and line fields regardless of the toggles.
Developer & Automation Access
Run it from the terminal
Same engine as this page, headless — via the gizza CLI:
gizza tool code-outline-extractor "class Greeter:
def hi(self):
return 1
def main():
pass"New to the CLI? Get gizza →
Open it by URL
Pre-fill and auto-run this tool with query parameters — the names match the API/CLI:
https://gizza.ai/tools/code-outline-extractor/?code=class%20Greeter%3A%0A%20%20%20%20def%20hi%28self%29%3A%0A%20%20%20%20%20%20%20%20return%201%0A%0Adef%20main%28%29%3A%0A%20%20%20%20pass&language=auto&format=tree&signatures=true&line_numbers=trueMachine-readable descriptor: tool.json — title + parameters JSON Schema for agents.