Excel to JSON Converter
Convert XLSX, XLS, ODS and CSV files to JSON right in your browser. Pick a sheet, configure options, then copy or download. Files are never uploaded.
Drop your Excel or CSV file here
or
Supports .xlsx · .xls · .ods · .csv
🔒 Private: Your file is read locally and never uploaded or stored. Works offline once the page loads.
What does Excel to JSON do?
Excel to JSON conversion turns spreadsheet data into a machine-readable format that developers, data engineers and analysts use to feed APIs, databases, scripts and configuration files. This tool reads your spreadsheet entirely on-device using the SheetJS library, so your data never leaves your computer.
Output format guide
| Mode | When to use | Example output |
|---|---|---|
| Array of objects | REST APIs, databases, most data processing | [{"Name":"Alice","Score":95}] |
| Array of arrays | Grid-based processing, spreadsheet mirrors | [["Name","Score"],["Alice",95]] |
| Minified | Embedding JSON in code or payloads | No whitespace, smallest file size |
| Indented 2/4 spaces | Readability, version control diffs | Pretty-printed, one key per line |
Frequently asked questions
- Is my Excel file uploaded anywhere?
- No. This converter runs entirely in your browser using the SheetJS library. Your file is read directly from your local disk into memory and never sent to any server. Close the tab and it is gone — nothing is stored.
- What file formats are supported?
- The converter accepts .xlsx (Excel 2007+), .xls (Excel 97–2003), .ods (LibreOffice / Google Sheets export), and .csv files. For CSV files the sheet selector is hidden because there is only one sheet. Macro-enabled workbooks (.xlsm) are accepted but macros are not executed — only data is read.
- What is the difference between "Array of objects" and "Array of arrays"?
- Array of objects (the default when "First row as headers" is on) produces JSON like [{"Name":"Alice","Score":95},{"Name":"Bob","Score":87}] — each row becomes an object keyed by the header row. Array of arrays produces [["Name","Score"],["Alice",95],["Bob",87]] — every row, including the header, is a plain array. Use array-of-objects when you need named fields (e.g. feeding a REST API or database). Use array-of-arrays when you want to keep the raw grid structure.
- What happens to empty cells?
- In array-of-objects mode, cells that are completely empty are omitted from the object (the key will not appear rather than being null). In array-of-arrays mode, empty cells become null. You can post-process the JSON to replace missing keys with null or a default value if your downstream code needs them.
- How large a file can I convert?
- There is no hard server-side limit because everything happens in your browser. In practice, most modern browsers can comfortably handle Excel files up to 10–50 MB. Very large files (hundreds of thousands of rows) may take a few seconds and use significant memory. If your browser tab crashes, try splitting the file into smaller chunks first.
- Can I convert a specific sheet from a multi-sheet workbook?
- Yes. When you load a workbook with more than one sheet, a sheet selector dropdown appears. Choose any sheet by name and the JSON output updates immediately. The Download button always downloads the currently selected sheet.