CSV ⇄ JSON

Convert between CSV and JSON formats

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Upload a .csv file. It will be parsed and converted to JSON automatically.

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À propos de cet outil

Spreadsheets speak CSV. Apps and APIs speak JSON. This tool converts between the two in your browser, so customer lists, exports and seed data never leave your device. Upload a CSV file and it is parsed into a JSON array of objects, one row per object, with column headers as keys. Paste or upload JSON and it becomes a downloadable CSV you can open in Excel or Google Sheets. Quoted fields, commas inside values and escaped quotes are handled properly rather than split naively. If a CSV is invalid, a popup shows the exact row and column that failed so you can fix it and try again.

Comment utiliser cet outil

  1. Choose the directionPick CSV to JSON or JSON to CSV at the top. Each mode accepts the matching file type and paste input.
  2. Upload a file or paste your dataDrop a .csv or .json file, or paste into the input box. Uploaded files are parsed and converted automatically.
  3. Check the outputValid data appears in the output panel with row and column counts. Invalid CSV or JSON opens a popup with the exact problem location.
  4. Copy or downloadCopy the result to the clipboard, or download it as a .json or .csv file ready to use elsewhere.

Pourquoi l’utiliser

  • Runs entirely in your browser, so spreadsheets and API payloads with personal data are never uploaded.
  • Proper CSV parsing for quoted fields, embedded commas and doubled quotes, which naive splitting gets wrong.
  • Clear validation when a file is invalid, with the row and column where parsing failed.
  • Works both ways: CSV to JSON for apps and APIs, JSON to CSV for Excel and Sheets.
  • No account, no upload limit and no watermark on the download.
  • Instant conversion with copy and download in one place.

Usages courants

  • Turning a spreadsheet export into JSON for an application, script or API.
  • Converting an API response into CSV so it opens in Excel or Google Sheets.
  • Preparing seed data for a database from a spreadsheet export.
  • Sharing a JSON dataset with a colleague who prefers a spreadsheet.
  • Moving data between two systems that each expect a different format.

Conseils pour de meilleurs résultats

  • Make the first CSV row your column headers. Those names become the JSON keys.
  • Use a flat array of objects for JSON to CSV. Nested objects are flattened into cell text and cannot round-trip cleanly.
  • If conversion fails, read the popup first. It usually points at an unclosed quote, a missing header or a mismatched column count.
  • Prefer UTF-8 when exporting from Excel. Accented characters look wrong when Excel opens UTF-8 without the right encoding selected.
  • For broken JSON syntax, run the payload through the JSON Formatter first, then convert here.

Erreurs à éviter

  • Expecting nested JSON to survive a round trip through CSV. CSV is flat, so depth is lost on the way out.
  • Omitting the header row, which turns your first data row into fake column names.
  • Uploading a file that is not CSV or JSON, then assuming the tool failed rather than the file type.
  • Splitting CSV yourself on commas. Quoted addresses and free text break that approach immediately.
  • Opening a UTF-8 download in Excel without choosing UTF-8, then blaming the converter for mangled characters.

Questions fréquentes

Choose CSV to JSON, upload your .csv file or paste the text, and the tool converts it automatically. Each row becomes a JSON object and the header row becomes the keys.

Choose JSON to CSV, paste an array of objects or upload a .json file. The keys become columns and each object becomes a row you can download as CSV.

A popup explains that the file is invalid and shows where it failed, including the row and column when possible. Common causes are unclosed quotes, empty headers, duplicate headers or rows with the wrong number of columns.

Yes. The first row is treated as column headers, which become the key names in the JSON output.

CSV is flat rows and columns, so nested objects or arrays are written as simplified cell text. Complex nested JSON will not keep a perfect structure in CSV.

No. Parsing and conversion run in your browser, which matters because CSV and JSON exports often contain customer records and internal data.

Fields with commas are quoted, and quotes inside those fields are doubled, following standard CSV rules. That is where splitting on commas by hand usually goes wrong.

Yes. There is no account, no per-file charge and no watermark. Because everything runs on your device, there is no server cost to pass on.

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