Effortlessly Convert Excel Files to CSV Using Microsoft Excel or Other Tools

Most verification and email tools prefer CSV, a plain text file with values separated by commas. Converting from Excel takes a minute.

In Microsoft Excel

1. Open the workbook and select the sheet that holds the addresses.
2. Choose File, Save As.
3. Pick CSV (Comma delimited) (*.csv) or CSV UTF-8 as the type.
4. Save. Excel warns that only the active sheet is saved; that is expected.

In Google Sheets

Open the sheet, choose File, Download, Comma-separated values (.csv). The current sheet is exported.

In LibreOffice Calc

Choose File, Save As, set the type to Text CSV, and keep the default separator unless your list uses semicolons.

Tips for a clean file

• Keep the addresses in the first column and remove empty rows.
• Choose UTF-8 so accented and Turkish characters survive.
• Trim leading and trailing spaces.
• Avoid merged cells and formulas; export values only.

Which CSV format should you choose

Excel offers several CSV options and the choice matters when another system reads the file.

• CSV UTF-8 (Comma delimited): the safest choice. It keeps accents and non-English letters intact and works in almost every modern tool.
• CSV (Comma delimited): uses your computer's older code page. Names with special characters can break.
• CSV (Macintosh) or CSV (MS-DOS): only for very old systems. Avoid them.
• Text (Tab delimited): useful when your data contains many commas, for example in addresses.

What Excel does not save

A CSV holds only the active sheet and only values. Formulas are saved as their results, formatting is lost, and other sheets are skipped, so export each sheet separately. If a workbook has several sheets you need, repeat the export for each one and give the files clear names.

Problems to check before you export

1. Merged cells. They leave empty cells in the file. Unmerge and fill every row first.
2. Hidden rows and columns. They are still exported. Delete what you do not want to send.
3. Commas inside a value. Excel wraps such values in quotes, which is correct, but check that your target system understands quoted fields.
4. Numbers stored as text and the reverse. Long identifiers and phone numbers should be Text before export so digits are not shortened.
5. Dates. A CSV stores the date exactly as it is displayed, so format the column the way the receiving system expects.
6. Leading and trailing spaces. They travel into the file. Use TRIM on text columns before exporting.

Other tools

• Google Sheets: File, Download, Comma-separated values (.csv) exports the current tab.
• LibreOffice Calc: File, Save As, choose "Text CSV" and tick the option to edit filter settings, where you set the encoding and the separator.
• Command line or scripts: for very large workbooks, a small script is faster and avoids Excel's row limit of about one million rows.

Exporting an email list for verification

For a mailing list, keep one column named email, one address per row, no merged cells and no extra header rows. Remove obvious blanks and duplicates. Export as CSV UTF-8 and the file is ready to upload to bulk email verification. You will get back a status for each row that you can filter before your next send.

Quick checklist

• Choose CSV UTF-8.
• Export one sheet at a time.
• Unmerge cells and fix text and number types first.
• Open the saved file in a plain text editor once to confirm it looks right.

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What happens to each data type

Excel keeps types inside the workbook, but a CSV has none. Everything becomes text, and what you see on screen is what gets written.

• Numbers: written as displayed. A value shown as 1,234.50 may be saved with the comma, which breaks systems that expect a plain number. Set a plain number format before exporting.
• Dates: written in the display format. 03/04/2026 is 3 April in some countries and 4 March in others. Prefer the unambiguous format 2026-04-03.
• Formulas: saved as their calculated result. The formula itself is gone, so keep the .xlsx as your source.
• Percentages: saved with the percent sign when formatted that way. Use a decimal column if the receiver wants a number.
• Line breaks inside cells: kept inside quotes. Some tools cannot read them, so remove them first.

Step by step in Excel

1. Click the sheet you want to export.
2. Remove merged cells, hidden columns and any rows above the header.
3. Check that the first row holds clear column names with no duplicates.
4. Choose File, Save As (on a Mac, File, Save As and the file format list).
5. Pick CSV UTF-8 (Comma delimited) and save.
6. Excel warns that only the active sheet is saved. Confirm once.

Check the result

Open the saved file in a plain text editor. You should see one record per line with values separated by the delimiter and quotes only around values that contain the delimiter. Compare the number of lines with the number of rows in the sheet. This takes thirty seconds and catches most export mistakes.

Doing it for many sheets

For a workbook with many sheets, exporting by hand is slow and error prone. A short script can read each sheet and write one CSV per sheet with a fixed encoding and delimiter. It is also the safest way to repeat the same export every week.

Mistakes that cost time

1. Saving over the original workbook. Always export under a new name.
2. Forgetting the encoding. The file looks fine on your machine and breaks on the receiving system.
3. Exporting filtered data without noticing. Hidden rows are still written. Clear filters or delete rows you do not want.
4. Leaving totals and notes under the table. They become rows in the file.

Preparing an email list

A clean list for a verifier has one column called email, no blank rows and no notes below the data. Remove duplicates before exporting so you do not pay to check the same address twice. Then upload it to bulk email verification and download the checked file.