Online JSON and YAML Structural Comparator
Compare JSON and YAML objects side by side to find missing properties and fields with different values. Automatic format detection makes it possible to compare JSON against YAML after both inputs are normalized into equivalent data structures.
This structural comparison focuses on parsed values rather than superficial indentation, quote style or YAML formatting, making it useful for API contracts and configuration reviews.
JSON and YAML Comparator
Compares two objects in JSON or YAML format by their fields, showing what exists in one but not the other and the fields that exist in both with different values. Nothing is sent to servers - the comparison runs locally in the browser.
How to use
Paste one object on each side (A and B). You can mix formats: in Automatic mode each side is interpreted as JSON and, if that fails, as YAML. Click Compare. The result appears below with both normalized objects (JSON with line numbers), highlighting different lines and showing three lists.
What is compared
The comparison is structural, field by field, using the full path (for example database.port or tags[1]). It lists fields missing on the left, fields missing on the right and fields with the same path (same level and name) but different values. Nested objects and lists are traversed recursively.
Note about YAML
The YAML parser covers the most common subset: mappings, lists, scalars (text, number, boolean, null), comments and flow style (similar to JSON). Advanced features such as anchors/aliases and multiline blocks (| and >) may not be supported.