Excel to CSV or JSON
- Drop an
.xlsx,.xlsor.odsfile. If it has several sheets, pick one, or tick All sheets. - Choose CSV or JSON (or a Markdown or HTML table) and set the options.
- Copy the result or click Download.
- CSV: choose a comma, semicolon (common in Europe, where the comma is the decimal separator), tab or pipe. The file is saved as UTF-8 with a byte order mark, so Excel opens accented characters and non-Latin scripts correctly.
- JSON: an array of objects keyed by the header row (best for APIs and JavaScript), an array of arrays (compact), or NDJSON for log pipelines and BigQuery. With "Numbers and true/false as JSON values" on, a column that holds only numbers becomes JSON numbers and a true/false column becomes booleans. A column of codes such as
007, or one mixing numbers and text, stays text, so every value in a column keeps the same type. - All sheets produces one JSON object with a key per sheet, or one CSV section per sheet.
CSV or JSON to Excel
Open a CSV or JSON file (or paste the data) and choose Excel (.xlsx). You get a real workbook, not a renamed CSV: numbers are stored as numbers so formulas and sorting work, column widths fit the content, and nothing is reformatted. JSON arrays of objects become one row per object, with nested fields flattened into columns such as address.city.
How values are converted
- Dates become ISO dates such as
2026-10-03, which every system understands, instead of Excel's internal day numbers. - Numbers are written without Excel's display formatting (currency symbols, thousands separators), so they import cleanly elsewhere.
- Formulas are converted to the values Excel last calculated.
- Empty rows are skipped and duplicate or blank column headers get unique names.
Everything happens in your browser: the workbook is never uploaded. For a closer look at the data first, open it in the CSV & Excel Viewer, or query it with SQL.
Frequently asked questions
How do I convert Excel to CSV?
Drop the Excel file on this page, choose CSV and the delimiter, then click Download. For a workbook with several sheets, pick the sheet or tick All sheets.
How do I convert Excel to JSON?
Open the file, choose JSON and a shape. Array of objects uses the first row as keys, which is what most APIs and JavaScript code expect.
Can I convert CSV to Excel?
Yes. Open or paste the CSV and choose Excel (.xlsx). Numbers are stored as real numbers and columns are sized to fit.
Why does Excel show strange characters in my CSV?
Excel assumes an older encoding unless the file starts with a byte order mark. Files downloaded here include it, so accents and non-Latin text display correctly.
Are my files uploaded?
No. Reading and converting happen in your browser; the file never leaves your computer.