My CSV opens as one column in Excel — why?

Excel expected a different separator (comma vs. semicolon). This converter detects it automatically.

Will dates be recognised?

ISO dates (2026-09-14) are stored as real Excel dates; ambiguous formats like 03/04/2026 are kept as text to avoid day/month mix-ups. You can convert them in Excel afterwards.

Is there a row limit?

Excel allows 1,048,576 rows per sheet. Larger CSVs are split across sheets.

Are my files uploaded?

No, the workbook is built in your browser.

Data & Spreadsheets

CSV to Excel

Opening a CSV directly in Excel mangles dates, strips leading zeros and misreads semicolons. Convert it here and get a clean workbook with the columns you expect.

Runs in your browser — files never leave your device.

Drop CSV, TSV, TXT files here

or click to browse · paste from clipboard · up to 100 MB each

Select files

Options

CSV separator

First row is a header

Detect numbers

Why convert CSV to Excel (XLSX)

Excel guesses a CSV’s separator from your regional settings and converts anything that looks like a number or date, which corrupts product codes (00123), phone numbers and ISO dates. This tool detects the delimiter and encoding and keeps text as text unless it is clearly numeric.

UTF-8 with accented characters, quoted fields containing commas or line breaks, and files from European systems with semicolons all convert correctly. Large files (hundreds of thousands of rows) are processed in your browser.

How it works

Drop CSV, TSV, TXT files onto the box above, click it to browse, or paste from the clipboard.
Adjust the options if you need to — the defaults suit most cases.
Press Convert. The work happens on your device, so speed depends on your computer or phone.
Download the Excel (XLSX) — individually or all at once.

About the formats

CSV · Comma-separated values · .csv

A plain-text table with one row per line and commas (or semicolons) between cells: the lowest common denominator for exchanging data.

CSV has no sheets, formulas, formatting or data types — everything is text.
European locales often use semicolons as separators because the comma is the decimal mark.
Values containing commas or line breaks must be wrapped in double quotes.

TSV · Tab-separated values · .tsv

Like CSV but with tabs between cells, which avoids the comma-versus-decimal problem and needs no quoting for most text.

Copying cells from Excel to a text editor produces tab-separated text.
TSV cannot contain literal tabs inside a cell without an escape convention.
Many database tools import TSV faster than CSV because there is no quoting to parse.

TXT · Plain text · .txt

Just characters, no formatting: the most portable format there is, opened by every editor ever written.

Plain text has no fonts, colours or images; only the words, line breaks and tabs survive.
Encoding matters: UTF-8 is the modern default; older Windows files may use Windows-1252 and show odd characters for accented letters.
Line endings differ between Windows (CRLF) and macOS/Linux (LF), which some tools care about.

Excel (XLSX) · Microsoft Excel workbook · .xlsx

The current Excel format: multiple sheets, formulas, formatting, charts and pivot tables in one file.

XLSX stores both the formula and its last computed value, so a converted CSV contains the values.
Maximum 1,048,576 rows and 16,384 columns per sheet.
XLSM is the same format with macros enabled.

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