Start with an array of objects
A single object at the root yields very few columns. Paste an array for list APIs. Deep nesting will not become multiple sheets on its own.
JSON Tools for AI Developers · Runs locally
Natural language generation · Schema · Zod · OpenAPI · Function Calling · MCP · 30+ tools
Ops hands you a CSV and you need a JSON array — or an API returns objects you need in Excel.
JSON → CSV uses object keys as headers. CSV → JSON builds an object array from the first-row headers.
Nested objects are flattened or stringified. For complex shapes, preview in Table first.
Conversion stays local. Customer lists don't need to hit a cloud drive first.
A single object at the root yields very few columns. Paste an array for list APIs. Deep nesting will not become multiple sheets on its own.
Duplicate names, empty headers, and stray spaces misalign fields. Clean the first row before you convert to JSON.
Shallow objects, yes. For deep nesting, flatten first or export only the columns you need.
A later column with the same name may overwrite the earlier one. Clean the CSV header first.
It follows common comma CSV. For tab-separated text, replace first, then convert.
No.
Usually an empty string or a missing key. Spot-check required columns after convert.
CSV has no types. On the way back to JSON, numbers may stay strings — convert them if you need to.
Add a header row first. Without one, the first data row becomes keys and the result is messy.
Table is a preview. This page converts to and from CSV.