CSV to Excel converter

Convert CSV to Excel without the usual mess

Opening a CSV directly in Excel is where things go wrong: everything lands in column A, leading zeros disappear, dates flip between day and month, and long IDs turn into scientific notation. Sehnna reads the raw file, decides the correct type for each column, and hands back a formatted .xlsx.

What gets fixed automatically

• Delimiter detection — commas, semicolons, tabs and pipes.
• Leading zeros preserved on postcodes, SKUs and account numbers.
• Dates parsed into real Excel date values with a consistent format.
• Numbers and currency typed properly instead of stored as text.
• Encoding issues cleaned up, so accents and umlauts survive.
• Header row styled, frozen and filterable.

How CSV to Excel conversion works

Upload the CSV, describe anything the file cannot tell us on its own — which column is a date, what currency the amounts are in — and Sehnna returns a formatted workbook. You can then ask for extra columns, a summary tab, or a chart without leaving the chat.

Step by step

• Upload your .csv or .txt export.
• Describe the columns and any formatting rules you need.
• Preview the formatted spreadsheet in the browser.
• Refine with prompts like 'add a total row' or 'split the name column'.
• Download as .xlsx, or keep working in Google Sheets.

Common CSV sources this handles

• Shop and marketplace order exports.
• CRM contact and lead exports.
• Analytics and ad-platform reports.
• Database query results and log exports.
• Payment processor payout and fee reports.

Tips for a clean result

• Keep the original header row in the file — it gives the AI the best hints.
• Say which column holds the primary date if several look like dates.
• Mention the currency so amounts are formatted rather than left bare.
• Ask for a separate summary tab instead of totals mixed into the data rows.