JSON Flattener

Convert nested JSON structures to flat key-value pairs with customizable options for delimiters, depth control, and array handling.

Input JSON

Flattened Output

Use . for dot notation, _ for underscore, etc.

Leave empty for unlimited depth

Keys containing any of these patterns will be removed from the flattened output

About JSON Flattening

What is JSON Flattening?

JSON flattening is the process of converting a nested JSON structure into a single-level flat structure where nested keys are represented using a delimiter (typically a dot). This is useful for:

  • Database Import: Convert nested JSON to flat rows for CSV/database import
  • Data Processing: Simplify data structures for easier programmatic access
  • Mapping: Create field mappings from complex nested objects
  • Configuration: Flatten config files for environment variables or simple storage
  • Analytics: Prepare data for analytics tools that expect flat structures

How It Works

Example:

Original JSON:

{
  "user": {
    "name": "John",
    "email": "john@example.com"
  }
}

Flattened Result:

{
  "user.name": "John",
  "user.email": "john@example.com"
}

Configuration Options

Key Delimiter

Choose how to separate nested keys:

  • • . (dot notation)
  • • _ (underscore)
  • • / (slash)
  • • Custom delimiter

Max Depth

Control nesting depth:

  • • Empty = unlimited
  • • 1 = only top level
  • • 2+ = nested levels

Array Handling

Three array processing modes:

  • • Index: user.0, user.1
  • • Ignore: skip arrays
  • • Stringify: array as JSON

Remove Keys by Pattern

Remove keys containing one or more patterns from flattened output:

  • • Multiple patterns: Click the "Add" button to add more filter patterns
  • • Pattern matching: Keys matching ANY pattern will be removed
  • • Example patterns: audioPath, imageUrl, metadata
  • • Output updates: Apply by clicking "Flatten JSON" button
  • Example: Remove audio/image paths, metadata, internal IDs, etc.

Find & Replace Values

Find keys by pattern and replace their values:

  • • Find: questions.0.id finds all keys with this pattern
  • • Replace: abc replaces matching key values with custom value
  • • Keep original: Original flattened output remains unchanged
  • • Multiple matches: All keys matching the pattern get the new value
  • Example: Replace question IDs, answer IDs, paths, etc. with uniform values