CSV to Excel Converter

What This Tool Does

The CSV to Excel Converter turns a CSV or TSV file into a real Excel .xlsx workbook you can open in Microsoft Excel, Google Sheets, or LibreOffice Calc. It reads the raw bytes of your file, figures out its character encoding and which delimiter separates the columns, parses the data with full support for quoted fields, and lets you review and adjust everything before building the workbook.

How to Convert CSV to Excel

1. Upload: Drop one or more CSV, TSV, or TXT files onto the drop zone, or click browse files.
2. Check the detected delimiter and encoding: Shown automatically above the preview - override either one if the file uses something unusual.
3. Toggle the header row: Leave First row is header checked if your file's first line contains column names.
4. Review the preview: Scroll the data preview to check the first rows, and set each column's type - Text, Number, Date, or Boolean - or leave it on Auto.
5. Choose sheet output: Keep everything in one sheet per file, or split rows into separate sheets based on a column's value.
6. Choose output mode: Convert each file to its own .xlsx, or combine every uploaded file into a single workbook with one sheet (or sheet group) per file.
7. Convert and download: Click Convert, then download each .xlsx individually, as a ZIP, or as a single combined workbook.

Delimiter and Encoding Detection

Not every CSV actually uses a comma. Exports from European spreadsheet software often use a semicolon, and tab-separated or pipe-separated files are common too. The tool samples the first lines of your file and picks whichever delimiter splits every line into the same number of fields most consistently. Character encoding is detected the same way - it checks for a byte order mark first, then falls back to UTF-8 or Windows-1252 depending on what decodes cleanly, so files exported from older Windows tools with accented characters still come through correctly. Both choices are shown above the preview and can be changed manually at any time.

Data Preview and Column Types

Before converting, you see the first rows of your file exactly as they'll be parsed, with a type selector above every column. Each column's type is inferred automatically by sampling its values - a column full of dates becomes Date, a column of numbers becomes Number, and so on - so cells land in Excel as real numbers and dates instead of plain text you'd have to reformat by hand. You can override any column's type manually if the automatic guess isn't what you want.

Multiple-Sheet Output Options

Choose Split into sheets by column and pick a column - for example "Region" or "Status" - and the tool creates one sheet per distinct value, so a single sales export becomes separate, ready-to-share sheets automatically. When converting several files at once, switch Output mode to Combine all files into one workbook to get a single .xlsx with one sheet (or sheet group) per source file, instead of a folder of separate files.

Validation Warnings

The tool flags problems before you download: rows with a different number of columns than the header (padded or truncated automatically), duplicate column names, and values that don't match the type you've selected for a column - for instance, text left in a column you set to Number. These show up as a warning list under the preview so you can fix the source file or adjust column types before converting.

Batch Conversion

Drop multiple files at once. Each gets its own row showing its row count and how many sheets it produced. Download files individually as they finish, or grab everything at once as a ZIP - or combine them into one workbook, as described above.

Privacy & Security

Your CSV file never leaves your device. Parsing, type detection, and the .xlsx file itself are all generated entirely inside your browser - no files are uploaded to any server, no account is needed, and there are no usage limits.

Frequently Asked Questions