JSON Merge Tool

Deep-merge two or more JSON objects with configurable strategies: concat arrays vs replace, last-wins vs first-wins on scalar conflicts. Useful for combining config files, layering overrides, or computing the union of API responses.

How to use the JSON Merge Tool

Paste two JSON objects. Deep-merge walks both trees: nested objects merge recursively, scalars resolve per the conflict strategy, arrays follow the array strategy. The result is the union with overrides applied.