Does Unflatten JSON upload my file or text to Tool-You servers?

No. Unflatten JSON runs in this browser tab. Files stay on the device. Limit note: Flat object only. Overlapping dotted paths fail. Max 500,000 characters.

Should I use Flatten JSON instead of Unflatten JSON?

Use Unflatten JSON when you need Rebuild nested JSON from dotted keys. Use Flatten JSON when you need Dot-path keys from nested JSON. They share a category (Convert) but not the same job.

What are the limits of Unflatten JSON?

Flat object only. Overlapping dotted paths fail. Max 500,000 characters. Also: Root must be a flat object. a.b becomes nested. Overlapping paths like a and a.b fail. Numeric keys stay object keys, not arrays.

Unflatten JSON

Rebuild nested JSON from dotted keys.

Root must be a flat object. a.b becomes nested. Overlapping paths like a and a.b fail. Numeric keys stay object keys, not arrays.

What Unflatten JSON does

Root must be a flat object. a.b becomes nested. Overlapping paths like a and a.b fail. Numeric keys stay object keys, not arrays.

Unflatten JSON sits in the Convert group on purpose. It is not Flatten JSON (Dot-path keys from nested JSON.) and not JSON Formatter (Pretty-print or minify JSON with indent and optional key sort.). Choose this page when you need Rebuild nested JSON from dotted keys. If you stretch Unflatten JSON into a neighbor’s job, the result will look wrong even though the site chrome looks the same.

How to use Unflatten JSON

Keep this tab on Unflatten JSON (/json-unflatten). Pasting into the wrong Convert tool (for example Flatten JSON) changes the job.
Paste or type the input Unflatten JSON expects. Path hint: json unflatten. Rebuild nested JSON from dotted keys.
Apply the Unflatten JSON action only. JSON Formatter is a different transform (Pretty-print or minify JSON with indent and optional key sort.). Root must be a flat object. a.b becomes nested. Overlapping paths like a and a.b fail. Numeric keys stay object keys, not arrays.
Copy the output of Unflatten JSON if you need it elsewhere. Size/complexity still follows: Flat object only. Overlapping dotted paths fail. Max 500,000 characters.
If the text job is actually Dot-path keys from nested JSON., leave Unflatten JSON and open Flatten JSON.

When not to use Unflatten JSON

Skip Unflatten JSON when a neighbor tool matches better — start with Flatten JSON or JSON Formatter — or when the description already warns the job will fail. In the tool’s own words: Root must be a flat object. a.b becomes nested. Overlapping paths like a and a.b fail. Numeric keys stay object keys, not arrays.

Questions about Unflatten JSON

What does Unflatten JSON do that other Convert pages on this site do not?: Root must be a flat object. a.b becomes nested. Overlapping paths like a and a.b fail. Numeric keys stay object keys, not arrays. Short version: Rebuild nested JSON from dotted keys.
Does Unflatten JSON upload my file or text to Tool-You servers?: No. Unflatten JSON runs in this browser tab. Files stay on the device. Limit note: Flat object only. Overlapping dotted paths fail. Max 500,000 characters.
Should I use Flatten JSON instead of Unflatten JSON?: Use Unflatten JSON when you need Rebuild nested JSON from dotted keys. Use Flatten JSON when you need Dot-path keys from nested JSON. They share a category (Convert) but not the same job.
What are the limits of Unflatten JSON?: Flat object only. Overlapping dotted paths fail. Max 500,000 characters. Also: Root must be a flat object. a.b becomes nested. Overlapping paths like a and a.b fail. Numeric keys stay object keys, not arrays.