What input formats are supported?

You can provide input as a flat JSON object or as a list of Key=Value pairs, one per line.

How does the tool handle arrays?

The tool supports numeric keys (e.g., user.0, user.1) or bracket notation (e.g., user[0], user[1]) to automatically detect and reconstruct arrays.

Can it automatically detect data types?

Yes, the 'Auto-detect' and 'Smart' inference modes automatically convert strings into numbers, booleans, or null values where applicable.

What happens if there are conflicting keys?

You can choose a merge strategy: override the existing value, merge objects/arrays, or trigger an error if a conflict is detected.

Is my data processed on a server?

The tool performs processing locally in your browser, ensuring your data remains private and secure.

JSON Unflattener | Online Free Tool

Examples

1. Reconstructing User Profiles

Backend Developer

Background

I received a flat list of user attributes from a legacy database export where keys were stored as 'user.profile.name' and 'user.profile.age'.

Problem

The application requires a nested JSON object to process the user data correctly.

How to use

Input the key-value pairs, set the Key Format to 'Dot Notation', and select 'Auto' for data type inference.

Input Format: Key=Value, Key Format: Dot Notation, Type Inference: Auto

Outcome

The tool outputs a clean, nested JSON object: { "user": { "profile": { "name": "John", "age": 30 } } }.

2. Parsing Configuration Arrays

DevOps Engineer

Background

I have a flat list of server settings using bracket notation like 'servers[0].ip' and 'servers[1].ip'.

Problem

I need to convert these flat strings into a structured JSON array for a deployment script.

How to use

Paste the lines, set Key Format to 'Bracket', and enable 'Bracket Keys' in the Array Detection settings.

Input Format: Key=Value, Key Format: Bracket, Array Detection: Bracket Keys

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Examples

1. Reconstructing User Profiles

2. Parsing Configuration Arrays

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