YAML ⇄ JSON Converter

Overview

Converts between YAML and JSON in both directions for the shapes that actually appear in service configuration: nested maps, typed scalars, inline arrays, and comments.

How It Works

Pick a direction. YAML to JSON walks the input by indentation, building nested objects and coercing scalars, so true and false become booleans, null and ~ become null, integers and decimals become numbers, bracketed lists such as [alpha, beta] become arrays, and # comment lines are dropped. JSON to YAML does the reverse with two-space indentation, keeping short scalar arrays inline and quoting any string containing YAML-significant characters. A parse failure reports the specific line it could not read instead of returning empty output.

Step-by-Step Usage Guide

1. Choose YAML to JSON, or JSON to YAML.
2. Paste the source document into the input pane.
3. Read the converted result, or the line-specific error if the input cannot be parsed.

Technical Specifications & Standards

This handles a deliberate subset of YAML rather than the full specification. Indentation-nested mappings, scalar type coercion, inline flow sequences and comments are supported. Block sequences written as dashed lines, anchors and aliases, multi-document streams, and folded or literal block scalars are not. That covers most Docker Compose, CI pipeline and Kubernetes-style fragments you paste to check a structure, but for a file leaning on anchors or multi-line strings use a full YAML library in your own toolchain.

Targeted Use Cases

• Translating a Docker Compose fragment into JSON to inspect its structure programmatically.
• Converting a JSON config into YAML for a pipeline that only accepts YAML.
• Sanity-checking indentation in a config file where the nesting looks ambiguous.
• Turning an API JSON response into YAML to read it more comfortably.

Notes & Gotchas

• YAML nesting is whitespace-significant and tabs are not valid indentation. Tabs are the most frequent cause of a parse error.
• Unquoted yes, no, on and off are booleans to YAML 1.1 parsers. Quote them when you mean the literal strings.
• A leading-zero value such as 0755 may be read as octal by some parsers, so quote it when it is a file mode.
• JSON has no comments, so comments in YAML input are dropped on conversion and cannot be recovered coming back.

Frequently Asked Questions