Transform

Remap and rename property keys across all objects in a JSON document or array

Remap property keys across JSON records to align with target API or database schemas.

🛡️ Your rows never leave your browser.

Why Onfyt: Renames keys in the structural JSON tree so string values matching key names are never accidentally corrupted.

Interactive Sample Data

id	first_name	last_name	user_email
1	Grace	Kerubo	grace@corp.com
2	Peter	Njoroge	peter@corp.com

How this tool works

Integrating data between different systems frequently runs into naming mismatches. A legacy billing system exports records with cryptic key abbreviations like '"fname"', '"lname"', and '"cust_num"', but your modern webhook receiver or GraphQL schema expects '"firstName"', '"lastName"', and '"customerId"'. Manually performing find-and-replace in a text editor to rename keys is hazardous: replacing 'id' with 'customerId' can accidentally overwrite internal data values, strings, or foreign keys that happen to contain the letters 'id' (such as 'valid' becoming 'valcustomerId'). DataFix parses your JSON into an abstract syntax tree and renames keys at the schema level without touching data values. You can map individual keys using a visual dictionary, or apply bulk casing transformations across the entire document: converting camelCase to snake_case, PascalCase, or kebab-case across all top-level and nested objects in a single click. Renaming property keys across JSON object hierarchies aligns legacy API responses with updated schema specifications without requiring backend modifications. Renaming JSON dictionary keys aligns legacy API outputs with modern schema specifications without requiring backend code rewrites.

Things that usually go wrong

Renaming to a key that already exists overwrites the existing value — the tool warns you.
Nested key renaming (inside an object within the array) requires dot notation.

Edge cases we tested

🧪 Values that match key names (e.g. {'status': 'status'})

Only the key is renamed; the data value remains untouched.

🧪 Nested keys inside child objects and arrays

Renamed consistently across all hierarchical levels.

🧪 Colliding keys (mapping two different keys to the same name)

Alerts user before overwriting to prevent data loss.

Frequently Asked Questions

Can I rename keys in nested objects?

Yes — use dot notation: 'user.firstName' → 'user.first_name'.

Can I rename all keys to snake_case at once?

Yes — enable 'Auto-convert to snake_case' mode.

Can I rename all keys to camelCase at once?

Yes — enable 'Auto-convert to camelCase'. first_name becomes firstName, last_name becomes lastName, and so on across all objects in the array.

Does the rename apply recursively to nested objects?

Yes — enable 'Deep rename' to apply the mapping to nested objects at all levels.

Related tools

Transform

Column to Comma-Separated List

Extract a CSV column and convert it to a comma-separated list for SQL IN clauses or code arrays.

Open Tool →

Transform

Comma-Separated List to Column

Convert a comma-separated, line-separated, or SQL IN list into a single-column CSV.

Open Tool →

Transform

Lines to CSV

Convert plain-text newline-delimited records into structured CSV tables.

Open Tool →