What does the JSON to CSV and CSV to JSON Converter do?
Use this tool when you need a browser utility that moves tabular records between JSON arrays, CSV, and TSV. It accepts an array of JSON objects or a CSV table with a header row and returns CSV, TSV, or an array of string-valued JSON records. Results are deterministic for the same input except where cryptographic randomness, current time, or a live provider response is part of the task.
CSV is a table, not a general object format
Choose CSV for flat rows consumed by spreadsheets or data tools. Keep JSON when records contain nested objects, arrays, typed numbers, booleans, or null values that must remain distinguishable.
How do you use it?
- Choose JSON → CSV, CSV → JSON, or CSV → TSV.
- Paste an array of flat JSON objects or a delimited table with a header row.
- Select Convert, verify the columns and quoting, then copy or download the result.
Worked example
Turn two flat records into CSV
Input
[{"name":"Ada","language":"JavaScript"},{"name":"Linus","language":"C"}]Output
name,language
Ada,JavaScript
Linus,CObject keys become the header row and each object becomes one record.
Common errors and fixes
| Symptom | Likely cause | Fix |
|---|---|---|
| JSON → CSV says the input must be an array of objects. | The top-level JSON value is an object, scalar, or nested structure rather than tabular records. | Wrap records in an array and flatten nested objects into scalar columns first. |
| CSV columns shift or parsing reports an error. | A value containing a comma, quote, or line break is not quoted correctly. | Wrap the field in double quotes and escape an embedded double quote as two double quotes. |
Important behavior of JSON ↔ CSV
Nested objects need flattening before CSV conversion because a cell is scalar.
Standards and implementation references
- RFC 4180 — Common Format and MIME Type for CSV Files (opens in a new tab)Documents conventional CSV records, headers, quotes, and line breaks.
- Papa Parse documentation (opens in a new tab)Documents the parser and serializer used by this page.
Frequently asked questions about JSON ↔ CSV
Does the JSON ↔ CSV upload my input?
No. Processing runs in the current browser tab, and the page does not send tool input to a KitLumi processing endpoint.
What input does the JSON ↔ CSV accept?
It accepts an array of JSON objects or a CSV table with a header row. The workspace checks the input and reports malformed or unsupported values before it produces a result.
What does the JSON ↔ CSV produce?
It produces CSV, TSV, or an array of string-valued JSON records. Copy and download controls appear when the output format supports them.
What limitation should I know?
Nested objects need flattening before CSV conversion because a cell is scalar.
What changed?
Added JSON to CSV, CSV to JSON, CSV to TSV, Header-row parsing, responsive controls, explicit runtime disclosure, and tested browser output.