What Is Nested JSON?
Nested JSON means JSON objects that contain other objects or arrays inside them, creating a hierarchical structure. For example, instead of a flat key like address_city, nested JSON uses {"address": {"city": "Moscow"}}. This structure matches how APIs and databases expect data, making integration seamless.
How Does Dot-Notation Mapping Work?
When your CSV has columns with dots in their names (like address.city, address.zip, items.0.title), the converter automatically creates nested objects. You can also manually edit the JSON path for any column in the preview table. Array notation is supported: items.0.title becomes {"items": [{"title": "Coffee"}]}.
Why No Other Tool Does This
- csvjson.com — only basic flat conversion, no nested mapping
- convertcsv.com — paid ($25/6mo), server-side upload required, no nested support
- Python/Node scripts — support nesting but require programming knowledge
- Our tool — visual dot-notation mapping, no code needed, 100% browser-side
How to csv to nested json online (3 Steps)
- Upload your CSV file — drag and drop or tap to select from your device
- Configure options — set delimiter, header row, type detection, and nested mapping
- Convert and download — click Convert, then copy or download your JSON file