Celtrim

CSV to Excel Converter

Turn a CSV file into a real .xlsx workbook with the separator detected, accented characters intact, and leading zeros kept. Nothing leaves your browser.

Nothing is uploaded — the text stays in this tab.

Free · no sign-up · processed on your device

Only have a PDF? Convert PDF to Excel with StatementConverterAI.

How it works

  1. 01

    Drop the CSV or paste it

    A .csv or .tsv file is read in your browser. The separator — comma, semicolon, tab, or pipe — is detected for you.

  2. 02

    Check the preview

    The first rows are shown as they will appear in Excel. Numbers are right-aligned; anything left-aligned stays text.

  3. 03

    Download the .xlsx

    You get a real workbook with a bold, frozen header row and filter arrows, ready to open in Excel, Numbers, or Google Sheets.

A CSV is plain text with no record of its separator, its encoding, or what type each column is, so whatever opens it has to guess. Excel guesses using your computer's regional settings, which is why the same file opens fine for one person and as a single column of garbled text for another. This converter reads the file the way it was actually written and builds a proper .xlsx, so the workbook looks the same on every machine. Need the opposite direction? Convert XLSX to CSV.

What opening a CSV in Excel gets wrong

Everything lands in column A
Excel splits a CSV on the separator your region uses, so a semicolon file opens as one long column in the US and a comma file does the same across much of Europe. The converter detects the separator from the data itself.
Accented letters turn into é and ł
Double-clicking a UTF-8 CSV without a byte order mark makes Excel read it in an old code page. The file is read here as UTF-8, with or without the BOM, so ł, é, ß, and emoji arrive in the workbook intact.
Leading zeros and long IDs disappear
007 becomes 7 and a 16-digit card or account number is rounded to 1.23457E+15. Numbers that start with a zero or run past 15 digits are written as text.
Values starting with = run as formulas
A cell beginning with =, +, or @ is executed when Excel opens a CSV. Those are stored as text in the workbook, which is also the standard defence against CSV injection.

Only want to look at the data? Open it in the CSV viewer instead. The table is stuck in a PDF? Convert PDF to Excel. The file came from a Mac as .numbers? Convert Numbers to Excel.

Common questions

How do I convert a CSV file to Excel?
Drop the .csv file onto the converter above. The separator is detected automatically, the parsed table is shown so you can check it, and the download is an .xlsx workbook. There is no import wizard and nothing to rename.
My CSV uses semicolons. Will it work?
Yes. Comma, semicolon, tab, and pipe are all detected from the file, and fields wrapped in quotes may contain the separator, line breaks, or doubled quotes. If detection ever picks the wrong one, choose the separator from the list.
Will Polish, German, or other accented characters survive?
Yes, as long as the CSV is saved as UTF-8, which is what Excel's CSV UTF-8 option, Google Sheets, and almost every export produce. A leading byte order mark is recognised and removed, and the text goes into the workbook unchanged.
Why not just open the CSV in Excel?
Excel guesses at the separator, the encoding, and every column type when it opens a CSV, and the guesses are where data gets damaged: leading zeros dropped, long numbers rounded, codes turned into dates. Converting first gives you a workbook where those decisions are already made correctly.
Is my file uploaded to a server?
No. The CSV is parsed and the workbook is built in your browser with local JavaScript. The file never leaves your device, and nothing is stored or logged.