TEXT & DEVELOPER TOOLS

CSV ↔ JSON Converter

Convert CSV to JSON and JSON back to CSV, with delimiter detection, a table preview and careful handling of numbers and nested data.

Quick answer: Paste or open CSV or JSON. The delimiter is detected for you, the preview shows the table, and you can copy or download the converted data.

By Vijay Kumar Singh · 20+ years in IT · Updated October 28, 2026

Use CSV ↔ JSON Converter ↓

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How to use CSV ↔ JSON Converter

Paste or open your dataCSV with commas, semicolons, tabs or pipes, or JSON in several shapes including JSON Lines.
Choose optionsHeaders, trimming, type detection, output shape, delimiter and quoting.
Preview and exportCheck the table preview, then copy or download. Use Swap to convert the result back.

Good to know

Common uses: Moving spreadsheet exports into APIs, turning API data into spreadsheets, and cleaning delimited files.

Practical example: Paste a CSV export, choose “array of objects” and get JSON ready for an API or script.

Important limitation: Values like 007 or long IDs stay text so they are not corrupted. Rows with the wrong number of fields are flagged. Cells starting with = + - or @ are protected against spreadsheet formula injection when exporting CSV.

For sensitive work, read the privacy information and follow your organization’s data-handling policy.

How it works

CSV is parsed with a quote-aware parser that handles quoted commas and line breaks. JSON is flattened with dot notation for nested objects, and big integers are kept exactly.

Real-world uses

Importing spreadsheet data into code
Exporting JSON to a spreadsheet
Fixing semicolon or tab-delimited files

Tips for better results

Keep “detect types” off if IDs must stay text.
Use semicolon output for spreadsheets in regions that use comma decimals.
Download CSV includes a BOM so Excel reads accents correctly.

Frequently asked questions

Does it detect the delimiter?

Yes: comma, semicolon, tab and pipe.

Will leading zeros or long IDs be changed?

No. Values like 00123 and very long numbers stay as text.

Does it handle nested JSON?

Yes. Nested objects are flattened to columns such as address.city, and arrays are stored as JSON text.

Does it support JSON Lines?

Yes, for both input and output.

Is my data uploaded?

No. Conversion happens in your browser.

Is the converter free?

Yes.