How do I convert JSON to CSV online?

Choose JSON → CSV, paste an array of objects (or a single object / NDJSON / wrapped array), pick a delimiter or preset, and copy or download the CSV. Nested objects flatten one level with dot keys such as address.city.

Can I convert CSV to JSON on the same page?

Yes. Switch to CSV → JSON or use Swap direction. The first row becomes object keys; each following row becomes one object. Quoted fields, embedded commas, and newlines are handled per RFC 4180. Optional type inference turns 42 and true into numbers and booleans. Unflatten rebuilds nested objects from dotted headers.

What does Unflatten dotted keys do?

When converting CSV → JSON, columns like address.city and address.zip become { "address": { "city": "...", "zip": "..." } }. JSON-looking cells such as ["math"] parse back into arrays. That is how you round-trip after editing flattened CSV in Excel.

What JSON shapes are supported?

Arrays of objects, a single object (one row), NDJSON (one object per line), and common wrappers like { "data": [...] }, results, items, records, or rows. Arrays inside values stay as JSON strings in the CSV cell until Unflatten parses them back.

What is the Excel EU preset?

European Excel often uses semicolon as the field separator and needs a UTF-8 BOM for accented characters. The Excel EU preset sets both in one click. Use RFC 4180 (comma, no BOM) for Google Sheets and most programming imports.

Is my JSON or CSV uploaded to a server?

No. Parsing, flattening, unflattening, and conversion run only in your browser. Nothing is uploaded - safe for API dumps and customer exports.

How is this different from other JSON to CSV sites?

One URL covers both directions with Swap, auto-detects NDJSON and wrapped API payloads, flattens one nested level for clean Excel columns, then Unflatten rebuilds nested JSON on the way back. Presets cover RFC 4180, Excel EU, TSV, and pipe - all without uploading your data.

Converter Tools

JSON to CSV Converter

Paste JSON or CSV and convert both ways on one page.

Everything runs in your browser. Pasted text and local files never leave your device - safe for API dumps and customer exports.

Drop a file here or click to browse

Accepts .json, .jsonl, .ndjson, or .txt (max 10 MB). Read locally - nothing is uploaded.

Output preset

Delimiter

Excel UTF-8 BOM

JSON input

2 rows6 columnsJSON array

Preview (first 2 of 2 rows)

id	name	address.city	address.zip	tags	active
1	Ada Lovelace	London	SW1A	["math","computing"]	true
2	Grace Hopper	New York	10001	["cobol","navy"]	false

CSV output

id,name,address.city,address.zip,tags,active
1,Ada Lovelace,London,SW1A,"[""math"",""computing""]",true
2,Grace Hopper,New York,10001,"[""cobol"",""navy""]",false

About JSON to CSV Converter

Paste JSON or CSV and convert both ways on one page. This free JSON to CSV Converter flattens nested objects one level (address.city), accepts arrays, single objects, NDJSON, and wrapped { data: [...] } payloads, and parses RFC 4180 CSV with quoted commas. On the reverse path, Unflatten rebuilds nested objects from dotted headers so you can edit in Excel and get structured JSON back. Use RFC 4180, Excel EU (semicolon + BOM), TSV, or pipe presets. Everything runs client-side - your API dumps never leave the browser.

How to Use JSON to CSV Converter

Choose JSON → CSV or CSV → JSON (or Swap direction after a conversion).
Paste your data, or drop a local .json / .csv file (max 10 MB - read in the browser only). Nested objects flatten one level; NDJSON and { data / results / items } wrappers are detected automatically.
Pick a preset (RFC 4180, Excel EU, TSV, Pipe) or set delimiter / Excel BOM manually. For CSV → JSON enable Unflatten to rebuild address.city into nested objects.
Review the preview table, then copy or download the result. Nothing is uploaded.

JSON to CSV Converter Examples

API array to spreadsheet

Paste [{"id":1,"name":"Ada"},{"id":2,"name":"Grace"}] and download a CSV with id,name headers ready for Excel or Google Sheets.

Flatten nested address

{"user":{"name":"Ada"},"score":10} becomes columns user.name and score - one nested object level, no deep recursion clutter.

Excel edit then unflatten

Convert nested JSON to CSV, edit address.city in Excel, switch to CSV → JSON with Unflatten on - you get { "address": { "city": "..." } } again, not a flat dotted key.

NDJSON / logs

Paste one JSON object per line (mongoexport, BigQuery, Loki). The tool detects NDJSON when the blob is not a single JSON value and builds one CSV row per line.

CSV with commas inside quotes

A cell like "hello, world" stays one field. Switch to CSV → JSON to get { "note": "hello, world" } with proper escaping.

Frequently Asked Questions about JSON to CSV Converter

How do I convert JSON to CSV online?: Choose JSON → CSV, paste an array of objects (or a single object / NDJSON / wrapped array), pick a delimiter or preset, and copy or download the CSV. Nested objects flatten one level with dot keys such as address.city.
Can I convert CSV to JSON on the same page?: Yes. Switch to CSV → JSON or use Swap direction. The first row becomes object keys; each following row becomes one object. Quoted fields, embedded commas, and newlines are handled per RFC 4180. Optional type inference turns 42 and true into numbers and booleans. Unflatten rebuilds nested objects from dotted headers.
What does Unflatten dotted keys do?: When converting CSV → JSON, columns like address.city and address.zip become { "address": { "city": "...", "zip": "..." } }. JSON-looking cells such as ["math"] parse back into arrays. That is how you round-trip after editing flattened CSV in Excel.
What JSON shapes are supported?: Arrays of objects, a single object (one row), NDJSON (one object per line), and common wrappers like { "data": [...] }, results, items, records, or rows. Arrays inside values stay as JSON strings in the CSV cell until Unflatten parses them back.
What is the Excel EU preset?: European Excel often uses semicolon as the field separator and needs a UTF-8 BOM for accented characters. The Excel EU preset sets both in one click. Use RFC 4180 (comma, no BOM) for Google Sheets and most programming imports.
Is my JSON or CSV uploaded to a server?: No. Parsing, flattening, unflattening, and conversion run only in your browser. Nothing is uploaded - safe for API dumps and customer exports.
How is this different from other JSON to CSV sites?: One URL covers both directions with Swap, auto-detects NDJSON and wrapped API payloads, flattens one nested level for clean Excel columns, then Unflatten rebuilds nested JSON on the way back. Presets cover RFC 4180, Excel EU, TSV, and pipe - all without uploading your data.

JSON Minifier & Formatter

Free online JSON minifier and formatter. Minify JSON to shrink payloads or beautify (pretty-print) JSON with 2-space indentation. Validates as you go - no upload required.

Unix Timestamp Converter

Convert Unix timestamps (seconds or milliseconds) into ISO 8601, UTC, and your local date/time. Convert local dates back into Unix seconds and milliseconds. Runs in your browser.

Diff Checker

Compare two texts side by side in your browser. Nothing is uploaded - safe for configs, logs, and contracts. Ignore whitespace or case, see word-level highlights, and copy a unified diff.