What Is JSON Merging?
JSON merging combines two or more JSON objects into a single object using deep merge semantics. Nested objects are merged recursively, and top-level keys are combined. This is essential when combining configuration files, API responses, or data sources.
JSON merging is useful for:
- Config Combination: Merging default and user config files.
- API Aggregation: Combining multiple API responses into one object.
- Data Enrichment: Adding fields from one data source to another.
- State Management: Merging application state updates.
How to Merge JSON Objects Online
- Paste JSON objects: Enter two or more JSON objects separated by newlines.
- Click Merge: Objects are deep-merged into one.
- Copy the result: Use the combined JSON.
Frequently Asked Questions
How are conflicting keys handled?
Values from later objects override earlier ones. For nested objects, merging is recursive — only leaf values are overridden.
How many objects can I merge?
The tool merges two objects at a time. For more, merge the result with additional objects.
Is this tool safe?
Yes. Processing is 100% client-side.
Related Tools
- JSON Formatter — Pretty-print merged JSON
- JSON Sort Keys — Sort keys in merged output