How to Convert Excel to CSV (And CSV Back to Excel) — Complete 2026 Guide

Converting an Excel spreadsheet to CSV — or bringing a CSV file back into Excel — is one of the most common data tasks people run into. Whether you need to import data into a database, feed a file into an analytics tool, or share clean data with a developer, this guide covers every method, every problem, and every question you will run into.

If you just need the fastest answer: use Transfonic's free convert Excel to CSV online free tool — upload your XLSX, download your CSV in seconds, no account required. For the full picture including the Excel manual method, Google Sheets, troubleshooting, and converting CSV back to Excel, read on.

What Is the Difference Between XLSX and CSV?

Before converting, it helps to understand what you are actually changing — because XLSX to CSV is not just a file extension swap. These are fundamentally different formats.

XLSX (Excel Spreadsheet) XLSX is Microsoft Excel's default format since Office 2007, built on the Open XML standard (ECMA-376 / ISO/IEC 29500). An XLSX file is actually a ZIP archive containing XML files that store your spreadsheet's data, formulas, cell formatting, multiple sheets, charts, and pivot tables. It is rich, powerful, and designed for working with data inside Excel or compatible tools like Google Sheets and LibreOffice Calc.

CSV (Comma-Separated Values) CSV is a plain text format where each row becomes a line and each column is separated by a comma. No formatting. No formulas. No multiple sheets. No charts. Just raw data — and that simplicity is exactly why every database, analytics platform, CRM, API, and programming language on the planet accepts CSV as input. RFC 4180 — the official CSV specification 

When to use each:

Part 1: How to Convert Excel (XLSX) to CSV

There are three practical methods. Method 1 is fastest for most people.

Method 1: Convert XLSX to CSV Online — Fastest, No Excel Required

If you do not have Microsoft Excel installed, or you simply want the fastest path, an online converter is your best option. Transfonic's convert Excel to CSV online free tool handles the conversion in your browser instantly — no signup, no watermarks, and your file is deleted immediately after conversion.

Steps:

1. Go to Transfonic's XLSX to CSV converter

2. Click the upload area or drag and drop your Excel file (up to 10MB)

3. Select CSV as your output format

4. Click Convert

5. Download your CSV file — done in under 10 seconds

Best for: Anyone who needs a quick, private conversion without installing software or creating an account. Your spreadsheet data never sits on a remote server.

Method 2: Convert XLSX to CSV Using Microsoft Excel

If you have Excel installed, you can convert directly using Save As.

Steps:

1. Open your XLSX file in Microsoft Excel

2. Click the tab of the sheet you want to export — important: CSV can only contain one sheet at a time

3. Go to File → Save As

4. In the "Save as type" dropdown, select CSV (Comma delimited) or CSV UTF-8 (Comma delimited) — choose UTF-8 if your data contains special characters, accented letters, or non-English text

5. Click Save

6. Excel will warn you that only the active sheet will be saved — click Yes to confirm

7. Excel may warn again about features that will be lost (formulas, formatting) — click Yes again

Important — what you will lose:

• All sheets except the active one

• All formulas (replaced by their calculated values)

• All formatting, colors, and fonts

• Charts, images, and pivot tables

Best for: Users who already have Excel and are exporting a single, simple data sheet.

Method 3: Convert XLSX to CSV Using Google Sheets

If you use Google Workspace or do not have Excel, Google Sheets is a free alternative.

Steps:

1. Go to drive.google.com and upload your XLSX file

2. Right-click the uploaded file and select Open with → Google Sheets

3. Once open, go to File → Download → Comma Separated Values (.csv)

4. Google Sheets will export the currently active sheet as a CSV file

Note: Like Excel, Google Sheets exports only one sheet at a time. If you have multiple sheets, you need to repeat this process for each one.

Best for: Users without Excel who are already in the Google Workspace ecosystem.

Common Problems When Converting XLSX to CSV

These are the issues that trip people up most often — and how to fix them.

Problem 1: "I lost all my other sheets" This is expected behavior. CSV is a single-sheet format — it cannot store multiple worksheets. If your XLSX has three tabs and you save as CSV, only the active tab is exported. To export all sheets, you need to convert each one separately, or use an online tool that handles multi-sheet workbooks.

Problem 2: "My special characters show as garbled text" This is a character encoding problem. When saving in Excel, choose CSV UTF-8 (Comma delimited) instead of plain CSV. UTF-8 encoding correctly handles accented characters (é, ü, ç), symbols, and non-English text including Arabic, Chinese, and Cyrillic. If you are using Transfonic's online convert Excel to CSV online free tool, UTF-8 output is handled automatically.

Problem 3: "My cells that contain commas are breaking the file" This is not actually a problem — Excel and proper converters automatically wrap any cell containing a comma in double quotes (e.g., "Seattle, WA") so the CSV structure is not broken. If you are seeing broken data, the issue is likely with the tool you used, not the format itself.

Problem 4: "My dates are showing as numbers" Excel stores dates as serial numbers internally (e.g., 45678 instead of 15/03/2025). When converting to CSV, some tools export the raw serial number instead of the formatted date. To fix this in Excel before converting: select your date column, format the cells as Text, then convert. Alternatively, use Transfonic which preserves date formatting in the output.

Problem 5: "I need to export multiple sheets as separate CSV files" Excel requires you to manually export each sheet one by one. For large multi-sheet workbooks, this is tedious. An online converter or a script is the faster path for bulk exports.

Part 2: How to Convert CSV Back to Excel (XLSX)

Going the other direction — importing a CSV file into Excel — is just as common. You have received a data export, a database dump, or a report as a CSV and need it in Excel for analysis.

Method 1: Convert CSV to Excel Online — Fastest

Transfonic's convert CSV to Excel online tool converts your CSV file to a properly formatted XLSX spreadsheet instantly — free, no signup, files deleted immediately.

Steps:

1. Go to Transfonic's CSV to Excel converter

2. Upload your CSV file

3. Select XLSX as your output format

4. Click Convert and download your Excel file

Best for: Quick, private CSV to Excel conversion without Microsoft Excel or any other software.

Method 2: Open CSV in Microsoft Excel

Steps:

1. Open Microsoft Excel

2. Go to File → Open and select your CSV file

3. Excel will open it directly — each comma-separated value lands in its own cell

Important: Do not double-click the CSV file to open it directly. This often causes Excel to misinterpret column widths or encoding. Always use File → Open from inside Excel for reliable results.

If your data is appearing in one column instead of separate columns: The CSV may be using a different delimiter — semicolons (;) instead of commas, or tabs. To fix this:

1. Go to Data → Text to Columns

2. Select Delimited and click Next

3. Check the correct delimiter (Comma, Semicolon, or Tab)

4. Click Finish — your data will split into proper columns

Best for: Opening a CSV when you already have Excel installed and want a quick result.

Method 3: Import CSV into Excel Using Power Query

For large CSV files, recurring imports, or when you need more control over data types, Power Query is the professional approach.

Steps:

1. In Excel, go to Data → Get Data → From File → From Text/CSV

2. Select your CSV file and click Import

3. Power Query preview opens — check that columns are split correctly

4. Set the correct data types for each column (text, number, date)

5. Click Load to import into Excel as a structured table

Best for: Large files, recurring data imports, or when data types need to be controlled precisely.

When Would You Need Other Excel Conversions?

Once your data is in the right format for your workflow, you may need to convert it further. Here are the most common next steps:

• Share a report as a fixed document: Use Transfonic's Excel to PDF converter to lock your spreadsheet into a print-ready PDF that looks identical on every device
  

• Publish spreadsheet data on a website: Use the Excel to HTML converter to turn your spreadsheet into an HTML table you can embed in any CMS or website
  

• Extract raw text from a spreadsheet: Use the Excel to plain text converter to strip all formatting and get clean text content
  

• Open Excel files in LibreOffice or OpenOffice: Use the Excel to ODS converter to convert XLSX to the open document spreadsheet format compatible with free office software

For a complete overview of every document conversion type available, read our complete document converter guide.

XLSX to CSV — Quick Reference Summary