Data Format Converter

CSV to XLSX Converter

Paste CSV or open a file to create an XLSX spreadsheet. The file is built entirely in your browser, so your data is never uploaded.

Paste text, or drop a file here

Preview

    Example

    CSV input

    id,name,zip,active,price
1,Ada Lovelace,02134,true,19.50
2,"Hopper, Grace",94103,false,7

    Preview

    id  |  name  |  zip  |  active  |  price
1  |  Ada Lovelace  |  02134  |  true  |  19.50
2  |  Hopper, Grace  |  94103  |  false  |  7

    How it handles tricky cases

    Leading zeros and long IDs

    Opening a CSV directly in a spreadsheet often turns 02134 into 2134 and rounds long IDs. Here, those values are stored as text and stay exactly as written.

    Dates

    Dates stay as text instead of being reinterpreted, since 03/04/2025 means different days in different countries.

    Formulas

    A value like =1+1 is stored as plain text, so it doesn't run when the file is opened.

    Size limits

    An XLSX sheet holds at most 1,048,576 rows and 16,384 columns, and each cell at most 32,767 characters. Larger files get an error or a note.

    One sheet

    A CSV has one table, so the workbook has one sheet, named Sheet1.

    Do it from code

    Python with pandas and openpyxl:

    import pandas as pd

pd.read_csv("in.csv", dtype=str).to_excel("out.xlsx", index=False)

    Questions

    Why not just open the CSV in a spreadsheet?

    You can, but spreadsheet apps guess each column's type when opening a CSV and can change your data. This keeps values as written.

    Is my file uploaded?

    No. The spreadsheet is created on your device.

    Can I set column types by hand?

    Not yet. Numbers are detected safely, or you can turn that off so everything is text.

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