JSON Key Renamer
Rename JSON object keys using an explicit mapping, optionally across nested objects, while rejecting collisions and preserving values.
Start with your input
Edit the example or replace it with your own text.
Choose your options
These settings are optional. Keep the defaults to get started.
How to use JSON Key Renamer
- Paste an object or an array of objects.
- Provide an old-key to new-key mapping and choose recursive or root-record renaming.
- Rename and review the result; any collision stops the operation.
Apply a simultaneous explicit mapping
Keys are renamed from their original spelling, not repeatedly passed through the mapping. This permits deliberate swaps when destination names remain unique. Values and array ordering are preserved. Recursive mode visits nested objects; nonrecursive mode handles the root object or each root array record and leaves nested values unchanged.
Reject data loss from collisions
If two original properties would produce the same destination key in one object, the tool reports an error rather than choosing a winner. The source is never mutated. Special names such as __proto__ are handled as data properties. The mapping controls keys only and does not transform string values, infer casing conventions, or validate the resulting document against your API schema.
Example input
{"first_name":"Ada","profile":{"last_name":"Lovelace"}}Will renaming one key cause it to be renamed again by another mapping entry?
No. Every destination is determined from the original key once, so mapping chains are not applied repeatedly.
Is input uploaded?
Processing takes place in your browser. This tool does not send your input or selected files to a conversion API.