Merge multiple JSON objects with deep merge, shallow merge and conflict resolution strategies
Developer Tools
About This Tool
JSON Merger is a browser-based tool that merges multiple JSON objects and arrays into one unified structure. It supports deep and shallow merge strategies with configurable conflict resolution — including overwrite, keep first, and concatenate arrays — for seamless data integration.
Key Features
- Deep and shallow merge strategies
- Array concatenation and deduplication
- Configurable conflict resolution
- Support for multiple JSON inputs
- Real-time merge preview
- One-click copy merged result
Use Cases
- Merge API responses from multiple endpoints
- Combine configuration files with overrides
- Consolidate JSON data from different sources
- Merge translation files for internationalization
- Combine user preferences with default settings
json
merger
combine
deep-merge
data
Frequently Asked Questions
What is the difference between deep merge and shallow merge?
Deep merge recursively merges nested objects, combining inner properties field by field. Shallow merge only merges top-level properties, replacing nested objects entirely rather than merging their fields. Use deep merge when you need to preserve nested structure details.
What conflict resolution strategies are available?
Three strategies are available: Overwrite (later values replace earlier ones), Keep First (ignores conflicting later values), and Concat Arrays (merges two arrays into one). You can select the desired strategy from the dropdown menu before merging.
How are arrays handled during merging?
When the conflict resolution strategy is set to Concat Arrays, arrays with the same key are concatenated into a new array. With Overwrite, the later array replaces the earlier one. With Keep First, the first array is preserved unchanged.
Is my data safe when using this tool?
Absolutely. All JSON parsing and merging happen locally in your browser. No data is uploaded to any server, keeping your configuration and data completely private.
How many JSON objects can I merge at once?
The tool starts with two input fields, and you can dynamically add more using the Add JSON Input button with no upper limit. At least two valid JSON objects are required to perform a merge.