Convert CSV to a JSON array of objects and back. Handles quoted fields and tabs. Runs in your browser, nothing uploaded.
Convert between CSV and a JSON array of objects. Handles quoted fields. Nothing is uploaded.
What the CSV / JSON converter does
Paste CSV (with a header row) and get a JSON array of objects, or paste a JSON array and get CSV back. Quoted fields, commas inside values and tab-separated files are all handled. It runs in the page, so your data never leaves the device.
Frequently asked questions
Does it keep the column order?
The JSON keys follow the first CSV header row; the CSV output uses the keys of the first JSON object.
What about large files?
Conversion is local, so there is no upload limit, though very large inputs are bounded by the device’s memory.
Is anything uploaded?
No. Parsing and serialisation happen in the page.
How to use it
- Paste your CSV into the first input box. The text should begin with a header row listing each column name.
- Choose the delimiter that matches your file. Select Comma for standard CSV, Semicolon for European-style exports, or Tab for TSV files.
- Paste a JSON array into the second input box to convert back to CSV, or paste CSV into the first box to produce a JSON array of objects. The result appears in the adjacent output box immediately.
- Copy the generated output from the result box. The data stays in your browser; nothing is sent to a server.
Where it comes in handy
A developer exports 340 rows of product data from a spreadsheet application that only outputs CSV. The API they are integrating with accepts JSON arrays. They paste the export, choose comma, and get a structured payload ready to send in under a minute.
A data analyst receives a 12 MB semicolon-delimited file from a French government open-data portal. Because the conversion runs locally, the entire file processes without hitting any upload limit. The resulting JSON keeps every decimal value from the original figures column intact.
A hobbyist builds a small dashboard that reads sensor readings stored as tab-separated values. Each file contains roughly 5,000 rows with 18 columns. The tool converts the full file to JSON in the browser so the JavaScript code can load it directly from a local path.
Worth knowing
- The converter treats the first row as headers. If your file has no header row, the generated keys will be named Column1, Column2, and so on.
- Nested JSON objects and arrays are not supported in the reverse direction. If your JSON contains nested structures, those values are converted to their string representation inside a single CSV cell.
- Very long numbers may lose precision because the tool parses numeric strings as JavaScript numbers. Values with more than 15 significant digits can be rounded during the round-trip from CSV to JSON and back.