Excel File Converter — XLSX, CSV, ODS, JSON
Convert spreadsheet and table files without uploading
Runs in your browser · nothing is uploaded
Drop a file here or choose one
Processed in your browser · Up to 20MB
A data conversion tool. Full preservation of charts, images, macros, external links and formatting is unsupported. Files are never uploaded.
CSV, TSV and JSON save the selected sheet only. JSON is a two-dimensional array including the first row. CSV/TSV cells are read as strings without automatic number or date conversion.
Formulas are not calculated here. Values mode uses saved results and stops if a formula has none. Turning it off includes original formulas in workbook output.
Up to 100 sheets, 50,000 rows per sheet, 256 columns and 500,000 total cells. Maximum ZIP expanded size: 80MB.
How to use
- Choose or drop an XLSX, XLS, ODS, CSV, TSV or JSON file.
- For text files, choose the input encoding and CSV delimiter. TSV always uses tabs.
- Select a sheet for preview and text output, then choose the destination format.
- Review saved formula values, UTF-8 BOM and CSV/TSV injection protection options.
- Convert and download the result.
Conversion rules
CSV/TSV cells remain strings, including number-like text such as 001. Workbook dates use internal numeric values and supported number formats. JSON contains raw cell values, so dates may appear as Excel serial numbers. Empty cells become null in JSON. Ragged JSON rows are padded with null to the table width; entirely empty rows at the end may be omitted. JSON integers outside the safe JavaScript range must be supplied as strings.
CSV/TSV injection protection prefixes string values starting with =, +, -, @, tab or carriage return with an apostrophe. This deliberately changes those values. Existing workbook formulas are included when retaining formulas. Use saved values when you cannot trust the original formulas.
Workbook output keeps all sheets with limited formatting fidelity. This is a data transfer tool; retain your original file. Password-protected files, ZIP64 and VBA preservation are unsupported.
Limits: 100 sheets, 50,000 rows per sheet, 256 columns and 500,000 total cells. ZIP workbook contents may expand to at most 80MB.
Example
Convert [["Name","Language"],["홍길동","한국어"],["你好","中文😀"]] from JSON to XLSX to create a table including its first row. Converting that workbook to CSV saves the selected sheet as UTF-8 text.
FAQ
Are files uploaded?
No. Reading and conversion happen inside your browser. The maximum input size is 20MB.
Does conversion preserve every sheet?
XLSX, XLS and ODS outputs contain all sheets. CSV, TSV and JSON output only the selected sheet.
Are formulas and formatting preserved?
By default formulas become their saved results. The tool does not calculate formulas and stops if saved values are missing. You may retain formulas, but full preservation of charts, images, macros, external links and formatting is unsupported.
Which JSON structure is supported?
Two-dimensional arrays of string, number, boolean and null cells. The first row remains a row rather than becoming object keys.
