WIN-J DATA TOOLS

JSON to CSV converter

Convert an array of JSON objects to a CSV table. Combine keys into columns, retain nested values as JSON cells, choose formula protection, and copy or download.

Free to useInput data is processed in this browser

Input JSON

Delimiter

CSV formula protection

Import a text file (optional)

UTF-8 CSV, TSV, TXT and JSON are supported. Selecting a file replaces the input; conversion starts only when you press Run.

Input and output are each limited to 2 MiB of UTF-8 text. CSV supports 10,000 rows and 200 columns, including transposed output. JSON allows depth 64 and 100,000 nodes; flattening allows 10,000 paths.

Formula protection adds an apostrophe before risky leading characters, tabs or newlines. This changes values, including negative numbers, and cannot guarantee protection after a spreadsheet is saved and reopened. Disable it only when you need unchanged values and can check the output.

Conversion result

Table preview

Only the first 10 rows and 12 columns are shown. Copy and download include the full result. This table shows original cells before formula protection; inspect the output text for any changes.

Full output to copy or save

Copy produces CSV without a BOM; downloads include a UTF-8 BOM. All cells are quoted. Formula protection adds an apostrophe to some original values.

Download result

How to use

Review the example, then paste input or import a UTF-8 text file.
Choose conversion options as explained below and press Run.
Review the full output and preview before copying or downloading.

Worked example

Two objects containing name, score and city become three columns, one header row and two data rows. Different keys are collected in first-appearance order.

Method and limits

The root must be a nonempty array of objects. Missing keys become empty cells; null becomes the text null. Nested values become JSON strings in individual cells. Limits: 10,000 rows including the header and 200 columns. Unsafe integers are rejected; decimals use JavaScript double precision. Enter long exact numbers as JSON strings.

Frequently asked questions

What happens to different keys and nested values?

All object keys become headers in first-appearance order. A missing key becomes an empty cell. Nested objects and arrays remain JSON strings in individual cells.

Is the input file uploaded to a server?

This tool processes input text and file contents in browser memory without sending them to a server. Refreshing discards the work. This is separate from ordinary site visit statistics.