Convert CSV to JSON online, free. CSV is a flat, row/column tabular format every spreadsheet and database understands. JSON is the dominant data-interchange format for web APIs and config. CSV to JSON conversion parses your CSV against the RFC 4180 grammar (https://www.rfc-editor.org/rfc/rfc4180), builds an in-memory model of its keys, nested objects and arrays, then re-serializes it as valid JSON following the ECMA-404 / RFC 8259 conventions. Processing runs in your browser in JavaScript with no upload or server round-trip — no size limit beyond your device's memory, so multi-megabyte documents convert in milliseconds and sensitive payloads never leave your machine. Typical uses include REST/GraphQL API payloads, app & build configuration and logging and analytics events.
It maps the full structure of your CSV onto well-formed JSON, following the ECMA-404 / RFC 8259 conventions. 100% free, no registration, and complete privacy — everything runs locally in your browser, so your data never touches a server.
Paste CSV and convert JSON immediately. Conversion runs client-side, so there is no upload wait and large documents stay fast.
Nested CSV objects, tables and arrays are mapped faithfully onto JSON.
Your CSV never leaves your device — everything is processed locally in JavaScript, with nothing logged or stored.
Unlimited conversions with no account, no quotas, and no watermark. Works on desktop and mobile.
A CSV document and its JSON equivalent:
CSV input:
name,age,email
Alice,30,[email protected]Output:
{
"name": "Alice",
"age": 30,
"email": "[email protected]"
}Paste your CSV into the editor and press "Convert to JSON". The tool parses it against the RFC 4180 grammar, then re-serializes it as JSON following ECMA-404 / RFC 8259 conventions — instantly and entirely in your browser. You can validate or format the CSV first to be sure it is clean.
CSV is flat and untyped: the header row supplies the field names and every column is read as text, so each row becomes one JSON record whose fields you may want to retype.
Numbers, booleans and null are preserved as native JSON types wherever JSON supports them, so standard documents convert losslessly and can be read back into the same structure.
CSV (Comma-Separated Values) (CSV) — CSV is a flat, row/column tabular format every spreadsheet and database understands. JSON (JavaScript Object Notation) (JSON) — JSON is the dominant data-interchange format for web APIs and config. This converter maps the structure of your CSV onto JSON so you can use it for REST/GraphQL API payloads.
Yes. Invalid CSV is flagged with a clear error before anything is converted. Common CSV problems to check are a consistent column count per row and proper quoting of fields that contain commas. Starting from clean input keeps the generated JSON accurate.
Yes. The entire CSV-to-JSON conversion runs locally in your browser in JavaScript — your CSV is never uploaded, logged or stored. That matters when the data is something like spreadsheet import/export, which should not leave your machine.
The generated JSON is ready for REST/GraphQL API payloads, app & build configuration and logging and analytics events. Copy or download it and drop it straight into your tooling.
CSV to JSON conversion turns tabular comma-separated data into a JSON array of objects, where the CSV header row becomes the keys and each subsequent row becomes one object. CSV (Comma-Separated Values) is a flat, spreadsheet-friendly format, while JSON (JavaScript Object Notation) is the structured format APIs and JavaScript work with natively. This tool parses your CSV following the RFC 4180 conventions — quoted fields may contain commas and line breaks, and a doubled quote ("") is an escaped quote — then emits clean, indented JSON entirely in your browser.
true/false, null, and numeric values become real JSON booleans, null, and numbers rather than strings.Convert a spreadsheet export into an API request body, load CSV datasets into a JavaScript app, seed a database from a CSV file, or transform analytics exports into JSON for further processing — all without uploading your data anywhere.
Yes. The header row supplies the JSON object keys; each following row becomes one object in the output array.
Yes. Unambiguous numeric, boolean, and null values are coerced to their real JSON types; everything else stays a string.
No. Conversion runs entirely in your browser — your data never leaves your device.
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