YAML Parser

What is YAML Parser?

YAML Parser loads a YAML document and shows it as a collapsible, searchable tree — the same interactive JsonTree view used across DevFormats — so you can inspect a config file's actual shape (which keys nest under which, where lists live) without a separate output file.

How it works

Input is parsed with js-yaml's load(), which supports YAML's default schema — nested maps and sequences, anchors and aliases, multi-line block scalars, and automatic typing of plain scalars (unquoted true/false/numbers/null). The parsed JavaScript value is handed directly to the tree view for display. On a parse failure, js-yaml throws a YAMLException carrying a mark object with an exact line and column, which the tool surfaces in the error bar and highlights in the input gutter — a more precise error location than XML's best-effort line extraction.

Features

• Collapsible, searchable tree view of the parsed document
• Supports anchors/aliases, multi-line strings, and standard scalar types
• Precise line/column error reporting from js-yaml's mark data
• Live re-parsing as you type
• Load a .yaml/.yml file directly from disk

Example

Input:

name: DevFormats
tools:
  - json-formatter
  - yaml-formatter
meta:
  free: true

Tree view shows the equivalent of: { name: "DevFormats", tools: ["json-formatter", "yaml-formatter"], meta: { free: true } }

Common errors

Mixing tabs and spaces for indentation is the single most common failure, since YAML uses indentation itself to express nesting and rejects tabs outright. A missing colon after a mapping key, or a list item indented at a different level than its siblings, also produce a YAMLException with an exact line/column pointing at the offending indentation.

Best practices

Use this tool to sanity-check how YAML anchors and aliases actually resolve — since the tree view shows the fully expanded values, it's an easy way to confirm an alias points where you think it does before that config file reaches production.