JSON ↔ YAML Converter

YAML and JSON are two faces of the same idea: human-readable structured data. JSON won the API war. YAML won the configuration war. Kubernetes, Docker Compose, GitHub Actions, OpenAPI, and Ansible all use YAML. Most of their underlying tooling speaks JSON. Bidirectional conversion is a daily need.

Why YAML for configuration?

YAML's indentation-based syntax and support for comments make configuration files significantly more readable than equivalent JSON. A Kubernetes deployment manifest with 40 fields is legible in YAML; the equivalent JSON would be a wall of braces and commas. Comments allow you to explain why a value is set — something JSON can't express.

Why JSON for APIs?

JSON's strictness (no comments, explicit quotes, no significant whitespace) makes it easier to parse reliably across all languages and environments. An HTTP API returning JSON has no ambiguity in how the response should be interpreted.

Common conversion scenarios

- Converting an OpenAPI spec from JSON (downloaded from Swagger UI) to YAML (for committing to a repo) - Transforming a Kubernetes manifest to JSON for programmatic manipulation - Migrating a config file from one format to another - Pasting YAML from documentation into a JSON-based admin tool

YAML gotchas

- Tabs vs spaces: YAML requires spaces for indentation. A tab character at the wrong place causes a parse error. - Implicit typing: `yes`, `no`, `on`, `off`, `true`, `false`, and bare numbers are automatically typed. Quote them if you want a string: `"yes"`, `"42"`. - Multi-line strings: `|` preserves newlines (literal block scalar); `>` folds newlines into spaces (folded block scalar). - The Norway Problem: `NO` is parsed as `false` in YAML 1.1. YAML 1.2 fixed this — this tool uses YAML 1.2 via js-yaml.