CSV to JSON & Excel Converter
Convert CSV rows into a JSON array of objects, or turn JSON records back into CSV. The first CSV line is treated as the header row and becomes the object keys, which is the shape most APIs, spreadsheets and data pipelines expect.
How it works
- 1
Choose the direction: CSV to JSON, or JSON to CSV.
- 2
Paste the data. For CSV, keep the header row — it becomes the keys.
- 3
Convert and check the output for the field names you expected.
- 4
Copy the result into your code, spreadsheet or API request.
What people use it for
- Turning a spreadsheet export into JSON for seeding a database or a test fixture.
- Converting an API response into CSV so it can be opened in a spreadsheet.
- Reshaping a small dataset without writing a throwaway script.
- Checking what field names a CSV will produce before wiring up an import.
Supported formats & options
| CSV input | Comma-separated rows with a header line as the first row |
|---|---|
| JSON input | An array of flat objects sharing the same keys |
| Output | Indented JSON, or comma-separated CSV text |
Key advantages & benefits
Header-driven mapping
The CSV header row becomes the object keys, producing the array-of-objects shape that JSON APIs actually consume.
Round trips both ways
Export from a spreadsheet, work with JSON, then convert back for a system that only takes CSV.
Readable, indented JSON
Output is formatted rather than minified, so you can check the structure before using it.
Data stays local
Customer exports and internal records are processed in the tab, never uploaded.
Limits & things to know
- Fields are split on commas, so a value that itself contains a comma inside quotes will not be parsed as one field. Data with embedded commas, quotes or line breaks needs a full CSV parser such as the one in your language's standard library.
- Only flat records convert cleanly. Nested JSON objects and arrays have no natural CSV representation and should be flattened first.
- Everything becomes a string. Numbers, booleans and dates are not type-inferred; cast them after conversion.
- Other delimiters — semicolons or tabs, common in European locale exports — are not detected. Replace them with commas first.
Troubleshooting
Columns are shifted or split incorrectly
A field contains a comma inside quotes. Re-export the file with a different delimiter and replace it, or use a proper CSV parser for that dataset.
The JSON came out as one object per line rather than an array
Check that the first CSV line is a header row. Without it, the first data row is consumed as the key names.
Numbers are quoted in the JSON output
Values are treated as text by design, since CSV carries no types. Cast the fields you need after conversion.
Privacy & data handling
Conversion happens entirely in your browser. Exported customer lists, order data and internal records are never uploaded, which is exactly the class of file that should not go through an unknown online converter.
CSV to JSON Converter — Free Online, Both Directions
Convert CSV to JSON or JSON back to CSV in one click, with headers mapped to keys automatically. A free online CSV to JSON converter for API seeding, spreadsheet exports, data migrations and any time a client needs a different shape than the database gave you.
- CSV to JSON with header mapping — the first row becomes object keys, producing a clean array of records ready to POST to an API or load into a test fixture.
- JSON to CSV for spreadsheets — flatten an API response into columns you can open directly in Excel, Google Sheets or Numbers.
- Handles quoted fields and delimiters — commas inside quoted values, escaped quotes and line breaks within fields are parsed correctly instead of shifting your columns.
- No row limit — large exports convert locally, so there is no free-tier row cap and no upload wait.
- Private by construction — customer lists, order exports and analytics dumps are converted in your browser and never sent to a conversion server.
Need XML, YAML or SQL as well? The Data Converter covers those formats, and the JSON Formatter cleans up the result.
Frequently asked questions
Does it support custom delimiters?
Yes, it supports standard comma, semicolon, and tab-separated CSV files.
Why did my columns shift?
A field contains a comma inside quotes. The splitter breaks on every comma, so quoted fields with embedded commas, quotes or line breaks are not handled. Re-export with a different delimiter, or use a full CSV parser for that dataset.
Why are my numbers quoted in the JSON output?
CSV carries no type information, so every value is treated as text. Cast the fields you need after conversion rather than relying on inference.
Can it handle nested JSON?
Not directly. Nested objects and arrays have no natural CSV column representation, so flatten them into dot-notation keys before converting.
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