CSV to JSON Converter
Turn any CSV export into clean JSON without your data ever leaving this page. The converter runs entirely in your browser — nothing is uploaded — and it is free with no signup. Drop a file or paste raw CSV text, check the preview, and download your JSON in seconds.
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CSV
CSV is the simplest and most universal tabular data format: one row per line, with values separated by commas, semicolons, or tabs. Every spreadsheet tool, database, and programming language can read and write it.
JSON
JSON is the standard data-interchange format of the web. It stores structured, possibly nested records in human-readable text and is the native format of most modern APIs and configuration files.
How the CSV to JSON conversion works
The parser first sniffs your delimiter — comma, semicolon, or tab — so European exports that use semicolons work without any configuration. The first row becomes the JSON keys (you can switch this off if your file has no header row), and numbers and booleans are typed automatically, so "42" becomes 42 rather than a quoted string.
Each remaining row is then mapped to one JSON object, and the result is a pretty-printed array of objects — the shape virtually every API, script, and framework expects. A preview of the first 50 rows lets you verify the columns before you download anything.
Frequently asked questions
- Is my CSV file uploaded to a server?
- No. Parsing happens in a Web Worker inside your browser tab. You can disconnect from the internet after the page loads and the conversion still works.
- My CSV uses semicolons — will it work?
- Yes. The delimiter is auto-detected between commas, semicolons, and tabs, and there is a manual override in the options panel if a file fools the detection.
- What happens to my header row?
- By default the first row supplies the JSON keys. Untick "First row is headers" and the converter generates column_1, column_2, … instead, keeping every row as data.
- How large can the file be?
- Up to 50 MB, which covers hundreds of thousands of rows for a typical CSV. Beyond that browsers run out of memory quickly, so we show a clear error instead of freezing the tab.