CSV Converter
Convert CSV to JSON or JSON arrays to CSV in your browser. Handy for spreadsheets, imports, and quick data checks.
CSV
Convert CSV to JSON, or convert a JSON array back to CSV. All processing is local.
Recent Payloads
Payloads you format will appear here for quick access. Stored locally in your browser.
What this tool does
Turn CSV with headers into a JSON array, or export JSON objects back to CSV for spreadsheets and imports.
Privacy
Conversions run on your device. Paste sensitive exports without uploading them.
Use cases
- Move tabular exports into JSON for APIs or scripts
- Flatten JSON logs into CSV for spreadsheet review
- Prototype data transforms before writing code
Troubleshooting
Seeing a row-width warning, or an unfamiliar __parsed_extra property in the output? CSV rows with a different number of fields explains what each case produces and how other parsers read the same file.
Got back far fewer rows than the file appears to contain, or a warning about a quoted field that was never closed? CSV unterminated quoted field covers why one stray quote absorbs every row below it.
Everything landing in one column when you open the file elsewhere? CSV opens in one column covers semicolons, commas, and why a correct file can still display wrongly.
Need the data as a Markdown table for a README or pull request? Markdown Table ↔ CSV converts in both directions.
Guides for this tool
- CSV encoding, UTF-8 and BOMJosé becomes José, and a stray  appears in the first column. That is a UTF-8 file being read as Windows-1252 — how to recognise it, and why the damage cannot be undone from text alone.
- Excel is changing your CSV dataA ZIP code loses its zeros, an ID becomes 1.23E+18, a product code turns into a date. The file is usually fine — the change happens when the spreadsheet reads it. How to check which.
- CSV opens in one columnEverything landing in column A does not mean the file is broken. Two causes look identical: the file uses semicolons, or Excel is splitting on your locale separator. Check the file first.
- Unterminated quoted fieldA quote that never closes makes the parser read every following line as part of one field. Measured: a three-row file parses as one row, and the row count is the symptom to look for.
- Rows with a different field countA row with more or fewer fields than the header is not invalid CSV — but every parser treats it differently. Measured across Papa Parse, Python csv, and Go: extra values, omitted keys, and hard errors.