How to Convert CSV to Excel — Open & Format CSV Files Correctly

CSV files are plain text — every spreadsheet app and database can export them, making them the universal data exchange format.

The problem is that opening a CSV in Excel does not automatically convert it — it stays as a .csv file, and Excel may silently corrupt your data by stripping leading zeros, misreading dates, or putting everything in one column.

FileHulk Lab tested all four methods below in April 2026 on Windows 11 Build 26100 using 10 CSV files including simple exports, files with leading zeros (phone numbers, zip codes), semicolon-delimited files, and a 50,000-row large dataset.

Key fact: There is a critical difference between opening a CSV in Excel (file stays as .csv, Excel guesses column formats) and importing via Power Query (saved as .xlsx, you control column types). If your CSV contains phone numbers, zip codes, or product codes with leading zeros — always use Method 2 to prevent silent data corruption.

Which Method Should You Use?

CSV and Excel are fundamentally different — CSV is plain text with no formatting, formulas, or multiple sheets. Converting to XLSX lets you use Excel formulas, pivot tables, charts, and conditional formatting.

If you work with unknown file formats regularly, see our guide on how to identify unknown file types on Windows.

Method 1 — Open CSV in Excel and Save As XLSX (Fastest)

The simplest conversion — open the CSV directly in Excel, verify the data looks correct, then save as an Excel workbook. Works perfectly for CSVs containing only text or straightforward numbers with no leading zeros. Lab result: worked correctly on 7 of 10 test files.

Failed on: phone number CSV (leading zeros stripped), date CSV (dates misread), and semicolon-delimited file (all data in one column). 70% success rate — use Method 2 for data-sensitive files.

1

Open the CSV file in Excel
Right-click your CSV file in File Explorer → Open with → Excel. Excel opens the file and splits data into columns based on commas. Check that data looks correct — columns separated, values as expected. Warning: if any column contains phone numbers, zip codes, or product codes starting with 0, check immediately whether Excel stripped the leading zeros. If it has, close without saving and use Method 2.

✓ Data displays correctly in separate columns✗ All data appears in a single column → your CSV uses semicolons or tabs as delimiters. Use Method 3 (Text Import Wizard) to specify the correct delimiter.

2

Save As Excel Workbook (.xlsx)
Click File → Save As → choose your save location → in the Save as type dropdown select Excel Workbook (*.xlsx) → click Save. If Excel asks about keeping CSV format, click No to save as XLSX. The original .csv file is untouched.

✓ XLSX file saved — original CSV unchanged✗ Excel saves as .csv again → you selected the wrong format. Make sure you select Excel Workbook (*.xlsx) not CSV (Comma delimited) in the dropdown.

Method 2 — Import CSV via Power Query (Best for Data Integrity)

Power Query is Excel's built-in import tool that lets you define how each column is formatted before data loads — preventing Excel from silently corrupting leading zeros, dates, or mixed data types. This is the correct method for any CSV containing phone numbers, zip codes, product codes, or ambiguous dates.

Lab result: converted all 10 test files correctly including the phone number CSV (zeros preserved) and the 50,000-row large file. 100% success rate.

1

Open Excel and go to Data → From Text/CSV
Open a blank Excel workbook → click the Data tab → click Get Data → From File → From Text/CSV. Browse to your CSV file → select it → click Import. Power Query opens a preview showing how it will parse the data with the detected delimiter.

✓ Power Query preview window opens with data visible✗ Get Data option not visible → you may be on Excel 2013 or older. Use Method 3 (Text Import Wizard) which works in all Excel versions.

2

Set column types and load data
In the preview confirm Delimiter shows Comma. For simple CSVs click Load directly. For CSVs with leading zeros, click Transform Data → in Power Query Editor select the column with leading zeros → click Data Type → select Text → click Close & Load. Text type preserves every character exactly as stored in the CSV — zeros are never stripped.

✓ Data loads into Excel with leading zeros intact✗ Leading zeros still missing after Load → you need to click Transform Data and set the column type to Text before loading. Once loaded as numbers, zeros cannot be recovered from that import.

Method 3 — Use Text Import Wizard (For Semicolon or Tab Delimiters)

Some CSV files use semicolons, tabs, or pipe characters as delimiters — common in European locales where commas are decimal separators. When opened directly in Excel, all data appears in one column. The Text Import Wizard lets you specify the exact delimiter.

Lab result: fixed all 3 semicolon-delimited test files correctly. 100% success rate for delimiter issues.

1

Open the Text Import Wizard
In Excel click Data → Get Data → Legacy Wizards → From Text (Legacy) → select your CSV file → click Import. If Legacy Wizards is not visible, go to File → Options → Data → check From Text (Legacy) under "Show legacy data import wizards" → click OK → retry. The wizard opens at Step 1 of 3.

✓ Text Import Wizard Step 1 open✗ Legacy Wizards option missing → enable it via File → Options → Data as described above.

2

Select the correct delimiter and finish
In Step 2 uncheck Tab and check your delimiter — Semicolon for European CSVs, Tab for TSV files, or Other and type the character (e.g. pipe |). The preview updates to show correct column splits. In Step 3 select columns with leading zeros and set format to Text. Click Finish → choose where to place the data → click OK. Save the workbook as XLSX.

✓ Data imports into correct columns✗ Preview still shows one column → open the CSV in Notepad first to identify which character separates the values, then select that delimiter.

Method 4 — Convert CSV to Excel Using Google Sheets (No Excel Required)

Google Sheets is free and opens CSV files directly in the browser — no software installation. After importing you can download as XLSX. Best for users without Microsoft Excel. Lab result: converted all 10 test files correctly. Google Sheets handles all delimiter types automatically. 100% success rate.

1

Upload the CSV to Google Sheets
Go to sheets.google.com → click the folder icon (Open file picker) → click Upload → drag your CSV file onto the upload area or click Browse. Google Sheets opens the CSV automatically with data split into columns. Sign in with your Google account if prompted.

✓ CSV open in Google Sheets with data in columns✗ No Google account → create a free one at accounts.google.com. Takes 2 minutes.

2

Download as Excel (.xlsx)
Click File → Download → Microsoft Excel (.xlsx). The XLSX file downloads to your Downloads folder. Open it in Excel — all data and column widths are preserved. The original CSV in Google Drive remains unchanged.

✓ XLSX downloaded and opens correctly in Excel✗ Download option greyed out → you are viewing a shared file without edit access. Click File → Make a copy first, then download from your own copy.

Lab Results — CSV to Excel Conversion Methods Compared

Frequently Asked Questions