JSON is a text format for exchanging structured data. A JSON value can be an object, array, string, number, boolean, or null.

Many md-utils commands produce JSON by default because it is predictable for programs and shell pipelines. For example, collection-oriented frontmatter commands return objects and arrays that preserve typed values instead of flattening everything into text.

Use JSON output when another program will consume the result. The companion tool jq can select, filter, and reshape that output without requiring a custom script.