CSV JSON Converter

How to use the CSV JSON Converter

1. Drop JSON, CSV, or TSV files here, or choose browse files. The file extension selects JSON to CSV or CSV to JSON.
2. For JSON input, inspect Records when several array paths are available. For CSV or TSV input, choose Delimiter and decide if First row is a header.
3. Set the options for nested objects, arrays, types, output shape, and exported fields.
4. Read the preview and warnings. Each valid file has a download control, and Download converted files handles all valid files.

JSON to CSV options for nested records

Turn on Flatten nested objects to turn a path such as address.city into a CSV column. Key separator sets the path style to dots, underscores, or slashes. With flattening off, nested object values reach the CSV row as their JavaScript string form.

Array handling changes how array values become rows. Join values in one cell writes the items in one cell, separated by semicolon and space. Expand into columns writes indexed fields such as tags.0. Expand into rows writes one row per array position and repeats non-array values.

Delimiter accepts Comma (,), Semicolon (;), Tab, Pipe (|), or Custom.... A custom delimiter can contain one character. Include header row adds or removes the header, and Quote all fields quotes every field. Use Fields to export, Select all, and Select none to choose the columns.

CSV to JSON output shape and type inference

Turn off First row is a header when the first row is data. The converter then names columns col1, col2, and so on. With Infer numbers, booleans & null on, recognized numbers, true or false, empty fields, and the word null become JSON values. Turn it off to keep parsed fields as strings.

name,age
Alice,34

[
  {"name": "Alice", "age": 34}
]

Enable Un-flatten column names and choose the matching Un-flatten separator to rebuild address.city as a nested object. Choose JSON array of objects for a list, or choose Object keyed by a column and then Key column to store each row under a field value. If a key repeats, the later row replaces the earlier property.

Preview limits and conversion warnings

The CSV preview shows the first 200 rows. The JSON preview shows the first 50 records when the result is an array. JSON to CSV output is capped at 20,000 rows and 200 columns per file, with a warning when the result is truncated. CSV parsing reports unterminated quoted fields and rows whose field count differs from the header.

Invalid JSON produces an error with a line and column when the parser can identify them. A CSV file with no parsed rows is marked as an error. Review warnings before downloading, because errored files are excluded from the valid downloads.

Input patterns that fit CSV JSON Converter

• A developer has JSON records, flattens nested keys, and sends selected columns to a spreadsheet.
• An analyst receives CSV with numeric and boolean text, enables type inference, and passes the JSON array to another script.
• A data editor receives a dotted column such as address.city, turns on Un-flatten column names, and restores nested JSON.

When another converter fits better

Use Spreadsheet Convert Tools to choose among spreadsheet conversion pages. To turn CSV or TSV into an Excel workbook, use CSV to Excel Converter. For XML output with mapped elements or attributes, use CSV to XML Converter. If each input line is a separate JSON object, JSONL CSV Converter matches the JSON Lines format.

Frequently asked questions