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Free CSV to JSON Converter

Upload or paste CSV and instantly convert it to clean, formatted JSON. Supports header rows, nested objects via dotted keys, and custom delimiters — all in your browser.

Delimiter:

Drop a CSV file here or click to browse — its contents load into the input box

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Your converted JSON will appear here. Click Convert to get started.
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CSV to JSON Conversion FAQ

Answers to the most common questions about converting CSV data to JSON.

Paste your CSV (or upload a file), choose your options, and click Convert. The tool parses the CSV with PapaParse, maps each row to a JSON object (using the header row as keys by default), and outputs formatted, syntax-highlighted JSON — entirely in your browser.
When enabled (the default), the first row of your CSV is treated as field names and each subsequent row becomes a JSON object keyed by those names, e.g. {"name":"Alice","age":"30"}. When disabled, each row is converted to a JSON array of values.
Enable Nested objects and any header containing a dot will be split into a nested structure. For example, a header address.city with value "NYC" becomes {"address":{"city":"NYC"}}. This is great for flattening hierarchical data into a single CSV.
The converter auto-detects the delimiter, but you can also force comma, semicolon, tab, or pipe. This is useful for European CSVs that use semicolons, or TSV (tab-separated) files.
Yes. When dynamic typing is on (default behaviour), PapaParse automatically converts numeric strings to numbers, true/false to booleans, and null to null. This produces cleaner JSON without quoted numbers.
No. Parsing runs entirely in your browser via the PapaParse library loaded from a CDN. Your CSV content and files never touch a server, so it is safe to convert sensitive data.
Yes. PapaParse is a fast streaming parser that handles large files well. Because everything is client-side, the practical limit depends on your browser's memory. For files of many megabytes, expect a short delay while the JSON is generated and highlighted.
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