Convert CSV files to Excel (.xlsx) using SheetJS. Preview the parsed data table before downloading. Set a custom sheet name. Auto-detects delimiters (comma, tab, semicolon). Handles quoted fields and line breaks within fields.
Drop a .csv file onto the upload zone or paste CSV text directly into the input. The tool auto-detects whether your data uses commas, tabs, or semicolons as delimiters. You can also manually select a delimiter.
A live table preview shows your data as it will appear in Excel — rows and columns identified, header row highlighted. Check that fields have parsed correctly before converting.
Click Convert to Excel to generate an .xlsx file using SheetJS in your browser. Enter a custom worksheet name (default: Sheet1). The file downloads immediately — no upload to any server.
CSV (Comma-Separated Values) is plain text — simple, portable, and readable by any text editor or spreadsheet app. It stores only data values with no formatting. Excel (.xlsx) is a binary format that supports multiple sheets, cell formatting, formulas, charts, and rich data types. Converting CSV to Excel is useful when you need to add formatting, formulas, or share with users who expect .xlsx files.
This tool reads CSV files as UTF-8, which covers most modern CSV files. UTF-8 handles accented characters, Chinese, Arabic, and other Unicode text correctly. If your CSV uses a legacy encoding like Windows-1252 or Latin-1, some special characters may not display correctly. Save your CSV as UTF-8 from your source application before converting.
Excel may auto-format certain values: phone numbers with leading zeros may lose the zero (e.g., "07911" becomes 7911), dates may be interpreted and reformatted, numbers in scientific notation may appear. To preserve text values exactly, the tool wraps ambiguous fields in Excel text format. Use the preview to check your data before downloading.
Comma (,) — the standard CSV format. Tab (\t) — TSV (Tab-Separated Values), common for data exported from databases. Semicolon (;) — used in some European locales where comma is the decimal separator. Pipe (|) — used in log files and some database exports. The tool auto-detects the most likely delimiter but you can override this manually.
This tool converts one CSV file per operation. For batch conversion of many CSV files to Excel, tools like Python with openpyxl (import openpyxl; ws.append(row)) or command-line LibreOffice (libreoffice --headless --convert-to xlsx *.csv) are more efficient. Microsoft Excel itself also imports CSV directly via the Data > Get External Data menu.
SheetJS and the browser can handle CSV files up to approximately 50–100 MB in size, limited by browser memory. Very large CSV files (millions of rows) may be slow to preview in the browser. Excel has a maximum of 1,048,576 rows and 16,384 columns per worksheet — if your CSV exceeds this, only the first 1,048,576 rows will appear in the .xlsx output.
