How to Convert CSV to Excel (.xlsx) Without Changing Your Data

The fastest route: convert in your browser

1. Open the CSV to Excel tool and choose your original .csv file.
2. Review the table preview. If fields appear together in one column, select the actual delimiter: comma, semicolon, or tab. If characters are unreadable, try the appropriate file encoding.
3. Download the .xlsx workbook. Open it in Excel and compare a few rows with the source CSV, especially identifiers, long numbers, and non-English text.

This site processes the file in your browser rather than uploading it to a server. It accepts CSV files up to 20 MB and supports UTF-8, UTF-16, Shift-JIS, and GBK/GB18030 input. The preview begins with ten rows and can expand to 100, but the export includes all parsed rows. Those preview limits are for browsing the data, not for truncating the workbook.

The converter writes the CSV fields as text. That is useful when 00127is an ID rather than the number 127, or when a long reference number must not be rounded by Excel. It also means a value that looks like a date or number remains text until you deliberately convert that column in Excel. Choose Excel's native import instead if you need typed numeric or date columns immediately.

Convert CSV to XLSX with Microsoft Excel

1. Open a blank workbook and choose Data > From Text/CSV. Pick the source file rather than double-clicking it.
2. Inspect the import preview. Set the delimiter and file origin or encoding so both the column boundaries and characters are correct.
3. Use the available transformation options to keep codes, ZIP codes, and long identifiers as text. Load the data, then save the workbook in Excel Workbook (.xlsx) format.

Excel's import controls are preferable when you need different types for different columns or want to add the data to an existing workbook. Microsoft describes the text and CSV import workflow. The exact menu labels vary by version and platform.

What conversion can and cannot preserve

CSV contains rows of text separated by a delimiter. It has no worksheets, formulas, fonts, or cell formatting to carry into an .xlsx file. Converting it creates a workbook around the data; it cannot restore formatting that never existed in the source. By contrast, if you already have an Excel workbook and need CSV files, use the Excel to CSV converter. It exports all worksheets by default or lets you choose one.

For example, a customer export might contain 000481,José,12-03-2026. The first field is often an identifier, not a number. The name depends on correct decoding, and the date may be ambiguous across regions. Check all three against the original text after conversion. If Excel already changed a value during a previous import, start over from the original CSV; changing a cell's display format may not recover the original characters. Microsoft's guidance on leading zeros and long numbers explains why text import matters.

A quick validation checklist

• The header and a later row have the expected number of columns.
• A code beginning with zero still begins with zero.
• A long identifier and any accented or non-Latin characters match the CSV.
• A quoted field containing a comma remains one cell rather than two.

If every field appears in a single column, follow the delimiter troubleshooting guide. If the main concern is how Excel interprets a CSV when opening it, see how to open a CSV in Excel without losing data.