Uwarp
sample.csvCSV (comma)5 data rows
timestamplevelservicemessage
2026-09-22T10:01:02ZINFOapiRequest started id=a1
2026-09-22T10:01:03ZWARNapiSlow query 240ms
2026-09-22T10:01:04ZERRORworkerJob failed retry=1
2026-09-22T10:01:05ZDEBUGapiCache hit key=user:42
2026-09-22T10:01:06ZINFOapiRequest finished id=a1 status=200

Drop a CSV file

.csv, .tsv, or .txt — max 10 MB

The download is an .xlsx workbook Excel can open. Conversion stays in this browser.

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Convert a CSV file to Excel

Convert a CSV file to an Excel workbook (.xlsx) in your browser. No signup, and the file stays on your device.

What is a CSV to Excel converter?

A CSV to Excel converter takes a comma-separated file and saves it as an Excel workbook. People use it when they need to convert a CSV file to Excel, or when a form asks for an XLS upload and they only have a .csv export. This page does that in the browser: you upload or paste CSV, check the table, and download an .xlsx workbook. Excel, Google Sheets, and Numbers open that file. It is the current Excel format, not the older binary .xls container.

CSV to Excel converter features

Save a spreadsheet export as a workbook you can open in Excel.

  • CSV to Excel workbook

    Upload a .csv or paste rows and download an .xlsx file with one sheet.

  • Header row

    The first row becomes the column titles in row 1 of Sheet1.

  • Numeric cells

    Plain numbers are stored as numbers. Text, IDs, and leading zeros stay as text.

  • Browser-side conversion

    The spreadsheet stays on your device. No account is required to convert CSV to Excel.

How to convert CSV to Excel

Three steps from a CSV file to an Excel workbook.

  1. Add the CSV

    Drop a .csv, .tsv, or .txt file, or paste the text. A sample table is loaded so you can try the download immediately.

  2. Check the preview

    Confirm the delimiter and whether the first row is the header. The preview matches the sheet that will be saved.

  3. Download the workbook

    Click Download Excel and open the .xlsx file. That is the file to use when a form asks for an Excel or XLS upload that accepts modern workbooks.

Tips for CSV to Excel

Get a cleaner workbook from a spreadsheet export.
  • 01

    Keep a header row

    Column names in the first row make the sheet easier to filter in Excel.

  • 02

    Leave IDs as text

    Codes with leading zeros stay text. Do not strip those zeros in the CSV if Excel needs them.

  • 03

    Watch the row cap

    The workbook includes the first 10,000 data rows and 256 columns. Split a larger export if you need every cell.

  • 04

    Open .xlsx, not a renamed CSV

    The download is a real Excel workbook. Renaming a .csv to .xls does not create this file.

Great for

Reasons to save CSV as an Excel workbook.

  • Excel uploads

    Turn a CSV export into a workbook when a form asks for an Excel file.

  • Sharing with non-CSV tools

    Send .xlsx to someone who sorts and filters in Excel or Google Sheets.

  • Keeping numbers numeric

    Plain numeric columns stay numbers so sums and sorts work after you open the file.

  • A fixed copy of an export

    Archive the table as a workbook next to the original CSV.

Why use this converter

A focused CSV to Excel path in the browser.

  • Free to use

    Convert CSV to Excel with no signup and no watermark on the download.

  • Private by default

    Parsing and workbook writing stay in the browser, which suits exports you do not want to upload.

  • No install

    Open the page, add the file, and download. Excel does not have to be installed to create the workbook.

  • Preview before download

    The on-page table shows headers and rows before the .xlsx file is created.

Technical details

How this CSV to Excel conversion works.
Input
CSV, TSV, semicolon, or pipe-delimited text up to 10 MB. Quoted fields follow common CSV rules.
Output
One .xlsx workbook with a single sheet named Sheet1. Plain numbers are numeric cells. Other values are text.
Limits
Up to 10,000 data rows and 256 columns. Larger exports need to be split before conversion.
Where it runs
Parsing and workbook writing happen locally in the browser. The file is not uploaded for conversion.

Sources & References

References for the CSV text format and the Excel workbook this converter writes.
  • “The comma separated values format (CSV) has been used for exchanging and converting data between various spreadsheet programs for quite some time.”
    — IETF — RFC 4180

    RFC 4180 — CSV: This tool reads comma-separated rows, including quoted fields, before writing them into an Excel sheet. datatracker.ietf.org/doc/html/rfc4180

  • “Office Open XML (also informally known as OOXML) is a zipped, XML-based file format developed by Microsoft for representing spreadsheets, charts, presentations and word processing documents.”
    — Wikipedia — Office Open XML

    Office Open XML: The download is an .xlsx workbook in that format, so current Excel can open the converted CSV as a spreadsheet. en.wikipedia.org/wiki/Office_Open_XML

Frequently Asked Questions

Quick answers about this tool—open a question to read more.