JSON Merge
Merge multiple JSON objects into a single object. Combine JSON data from different sources, merge configurations, or combine API responses. Supports deep merging with customizable merge strategies.
When to use this tool
You need to combine configuration objects or API responses.
You want to merge defaults with environment overrides.
Examples
Merge with overwrite
Input
A: {"timeout":30,"retries":2}
B: {"timeout":10}Output
{"timeout":10,"retries":2}Later keys overwrite earlier keys by default.
Developer use cases
Merge app config with per-environment overrides.
Combine multiple JSON fragments into a single payload.
Common mistakes to avoid
Expecting arrays to merge by index instead of overwrite/concat.
Overwriting nested objects unintentionally without deep merge.
Format and behavior notes
Default behavior overwrites duplicate keys from later inputs.
Deep merge can combine nested objects recursively.
Related guides
Related Tools
Frequently Asked Questions
How do I merge JSON objects?
Paste multiple JSON objects into separate input fields or combine them in one field. The tool will merge them into a single JSON object.
What happens with duplicate keys?
By default, values from later objects overwrite earlier ones. You can choose deep merge mode to merge nested objects recursively.
Can I merge arrays?
Yes, the tool supports merging arrays. You can choose to concatenate arrays or merge them based on your needs.