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Convert CSV to Excel
Create a real .xlsx workbook from CSV in your browser while keeping every source cell as text.
CSV → Excel (.xlsx)
The selected CSV and generated download stay in this browser tab.
Output contract
What the Excel (.xlsx) converter writes
The workbook contains one sheet with the CSV header and rows. Values are written as strings, preserving leading zeroes, identifiers, date text, and formula-like text instead of guessing cell types.
The same 50 MB CSV input limit and production parser used by the viewer apply here. The generated file is created only after parsing succeeds.
Plain answers
Excel (.xlsx) conversion questions
Is this a real Excel (.xlsx) file?+
Yes. The browser uses a format-native writer to create a valid .xlsx file, not a renamed CSV.
Is my CSV uploaded?+
No. The selected file is read and converted in this browser tab. Loading the page, code, or bundled sample still makes ordinary web requests.
What happens to data types?+
All source cells remain strings. This preserves identifiers and leading zeroes and avoids guessing that a date, boolean, or formula-like value has another meaning.