Similar Tools

JSON Flatten

Flatten nested JSON objects to flat key-value pairs using dot notation.

JSON Key Renamer

Rename keys across nested JSON objects and arrays.

INI to JSON

Convert INI configuration files to JSON and back with type inference.

JSON Key Extractor

Select which keys to include or exclude from a JSON array of objects.

Tone Generator

Generate sine, square, sawtooth, and triangle audio tones from 20 Hz to 20 kHz directly in your browser. Adjustable volume.

Split PDF by File Size

Split a PDF into smaller parts that each stay under a target file size in megabytes. Ideal for email attachments and upload limits.

USD & USDZ Converter

Convert GLB, OBJ, STL and FBX models to USDZ for iOS AR Quick Look, or read USD files back out.

apps

More Tools

Browse our full collection of free online tools.

JSON Unflatten

A JSON unflatten tool rebuilds nested structures from flat key paths. If you have data where keys look like user.address.city or items.0.name, this tool can turn those flat entries back into properly nested objects and arrays.

Why this matters

Flattened JSON is often convenient for export and storage, but not always ideal for application logic or configuration files. When you need the original hierarchy back, unflattening saves you from rebuilding the object structure manually.

What you can control

The tool lets you choose the separator character and optionally reconstruct arrays from numeric keys. That makes it flexible enough for different flattening conventions used by APIs, data pipelines, and custom scripts.

Because everything happens locally in the browser, you can safely restore nested JSON from flat data without uploading internal structures anywhere.