JSON Flattener

Flatten deeply nested JSON objects into flat key-value pairs with dot or custom notation.

How It Works & Processing Standards

Flatten deeply nested JSON objects into flat key-value pairs with dot or custom notation.

Your input data is never sent to any server and is securely processed on your device.

Current Limits

  • Desktop max file size: 50MB
  • Mobile max file size: 20MB

JSON Flattener is a 100% free, browser-based online utility. All calculations and file conversions run locally inside your browser (Local-First) without sending data to remote servers, keeping your documents and inputs strictly private.

How to Use JSON Flattener

  1. 1
    Input JSONPaste your nested JSON document.
  2. 2
    Choose SeparatorSelect dot (.) or custom delimiter for path keys.
  3. 3
    Copy Flat JSONCopy the single-level key-value JSON structure.

Examples

Flattened Object
Input: {"user": {"profile": {"name": "Alice", "city": "Seoul"}}}
Result: { "user.profile.name": "Alice", "user.profile.city": "Seoul" }

Common Use Cases

  • Preparing hierarchical JSON data for SQL table ingestion or CSV export
  • Flattening application state for analytics events and logging
  • Simplifying key lookups in configuration management dictionaries

Frequently Asked Questions (FAQ)

Can arrays be flattened as well?

Yes, array elements are flattened using their numerical indices (e.g. items.0.id).

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