Free browser-based data tool

JSON Property Copier

Copy one or more JSON properties to new locations instantly.

Your files never leave your computer.All processing happens locally inside your browser.

  • Map multiple source properties to new names or paths
  • Block conflicts without overwriting existing values
  • Copy or download pretty or minified JSON
1

Upload JSON

Choose a .json file. It is read only by this browser tab.

Drop a JSON object array file here

or use the file browser

2

Paste and validate a JSON object array

UtilityDock discovers exact source properties and nested paths.

Paste JSON or upload a file to begin.

What JSON property copying is

Duplicate values without removing their source properties

Property copying reads an exact source path and writes the same JSON value to a new property name or nested destination. Original properties remain unchanged, records stay ordered, and conflicts are blocked before output is created.

Schema migration

Support old and new field names during a transition

Copy customerId to accountId or retain a legacy property while a new schema rolls out. Representative data can carry both names without a script or destructive rename.

API compatibility

Add aliases expected by another integration

Duplicate identifiers, status values, or nested contact fields when two API consumers expect different paths. Missing sources are skipped and counted; existing destinations are never overwritten.

Data transformation workflows

Prepare alternate paths for downstream tools

Build a compatibility layer before conversion, testing, or import. Multiple mappings run together, while pretty and minified output options fit both review and machine workflows.

Examples

Copy exact source paths to intentional destinations

Source propertyDestination propertyUse
idlegacyIdPreserve a compatibility alias
profile.emailcontact.primaryEmailCreate a nested API path
statusmetadata.statePrepare a downstream schema

Modification utilities

Continue with related UtilityDock JSON workflows

FAQ

Questions about copying JSON properties

Does UtilityDock upload or store my JSON?

No. Your files never leave your computer. Validation, field discovery, property copying, conflict detection, preview, copying, and download creation all happen locally inside your browser.

What JSON shape can I use?

Version 1 accepts a non-empty array of JSON objects at the document root.

Can I copy more than one property?

Yes. Enter a destination for every detected source property you want to duplicate, then apply all mappings together.

Can a destination use a nested path?

Yes. Dot paths can create nested objects, and indexed array paths can target existing or newly created array containers when their structure is compatible.

What happens when a destination already exists?

UtilityDock blocks the operation and identifies the affected array item. Existing destination values are never overwritten.

What happens when a source property is missing?

That mapping is skipped for the affected record. The summary reports how many missing source values were skipped.

Does copying change my original property?

No. The original property remains in place with the same JSON value. New destination properties are appended whenever practical.

Can copying be conditional?

No. Version 1 uses exact source and destination paths. It does not support expressions, conditions, regular expressions, or APIs.