What is JSON object merging?

JSON object merging is the process of combining two or more JSON objects into a single unified object. This operation is essential in configuration management, API response composition, and data aggregation. Unlike array merging, object merging involves deciding how to handle conflicting property keys and nested structures. Different merge strategies exist: shallow merge (top-level properties only), deep merge (recursive merging of nested objects), and overwrite (complete replacement).

Tool description

A powerful JSON object manipulation tool that merges and combines multiple JSON objects with flexible strategies. This JSON object merger supports three merge strategies: shallow merge for top-level property merging, deep merge for recursive nested object combination, and overwrite mode for complete replacement. The tool validates JSON syntax, handles complex nested structures, and provides real-time merging as you input or modify your data.

Features

  • Three Merge Strategies: Choose between shallow merge, deep merge (recursive), or overwrite mode
  • Real-time Merging: Automatically combines objects as you type or paste JSON data
  • JSON Validation: Validates that both inputs are properly formatted JSON objects (not arrays)
  • Syntax Highlighting: Advanced JSON editor with syntax highlighting for easy reading and editing
  • Deep Merge Algorithm: Intelligently merges nested objects recursively while preserving structure
  • Error Handling: Clear error messages for invalid JSON or array inputs
  • Complex Structure Support: Handles deeply nested objects with multiple levels
  • Preserves Data Types: Maintains all original data types during the merge operation
  • Empty Object Handling: Works correctly even when one or both objects are empty

Merge Strategy Details

  • Shallow Merge: Merges only top-level properties; nested objects from second object overwrite those in first
  • Deep Merge: Recursively merges nested objects, combining properties at all levels
  • Overwrite: Second object completely replaces the first (if non-empty)

Use Cases

  • Configuration Management: Merge default configuration with user-provided overrides
  • API Response Composition: Combine data from multiple API endpoints into single response
  • Settings Consolidation: Merge application settings from multiple sources (defaults, environment, user)
  • Data Enrichment: Combine base data with additional metadata or computed properties
  • Environment Configuration: Merge base config with environment-specific overrides
  • Theme Customization: Combine default theme with user customizations
  • Feature Flags: Merge default feature flags with environment or user-specific flags
  • Microservices Data: Consolidate responses from multiple microservices into unified object