Updated November 1, 2026
Formatted Excel output, free
CSV to Excel, free and formatted
Upload a CSV and Operelio turns it into a formatted Excel workbook. Columns are auto-sized, headers are bolded, and values come through exactly as uploaded: no silent conversion to scientific notation, no lost leading zeros. Ready to share or present without any manual formatting.
No credit card required. Free for up to 2,000 rows.
What it does
A polished workbook from a plain text file
IDs stay intact
Long numeric IDs and leading-zero codes come through as text, so a long phone number or a 01234 ZIP doesn't get mangled into scientific notation like it would when double-clicking a CSV in Excel.
Auto-sized columns
Column widths are sized from the actual data (sampled across the first 100 rows), capped at 50 characters. The file opens ready to read without resizing.
Bold, readable headers
The first row is bolded so headers stand out. One professional detail that makes the workbook look hand-formatted the moment it's opened.
Works in every spreadsheet app
The .xlsx output opens in Microsoft Excel, Google Sheets, Apple Numbers, and LibreOffice Calc. Same file, every platform.
No desktop Excel needed
Convert in your browser on any OS. No license, no Text Import Wizard, no Save As dance. Up to 2,000 rows on Free, 50,000 on Starter, 75,000 on Pro, 150,000 on Agency.
Ready to hand off
The workbook is formatted the same way every time, so you can drop it into a client folder, an email attachment, or a shared drive without touching it first.
How to use it
Three steps to a formatted workbook
Upload your CSV
Drag and drop any .csv file, comma, semicolon, tab or pipe separated. Operelio reads the headers and data for you.
contacts_export.csv
5,875 rows, 9 columns
Preview the output
Check the formatted preview. Bold headers and auto-sized columns are applied, and every CSV value comes through as uploaded.
Download your workbook
Click Convert to Excel and download a .xlsx file that opens in Excel, Sheets, or Numbers. Ready to share or present.
Doing it yourself
How to open a CSV in Excel without breaking it
Double-clicking a CSV opens it with Excel's default settings, which strip leading zeros, show long numbers in scientific notation, and can turn codes into dates. Use Data > From Text/CSV instead, and set those columns to Text before the data loads.
Import a CSV with From Text/CSV
- 1Open a blank workbook and go to Data > From Text/CSV.
- 2Pick the CSV and click Import. Check the delimiter in the preview.
- 3Click Transform Data to open the Power Query Editor.
- 4Click the header of each ID, ZIP or phone column and choose Home > Data Type > Text. If Excel asks, pick Replace current.
- 5Click Close & Load. The data lands on a new sheet with those columns kept as text.
Convert the CSV to an Excel file
Opening a CSV doesn't change it: the file is still a .csv until you save it as something else. Go to File > Save As and pick Excel Workbook (*.xlsx) to keep the columns and any formatting you add.
Paste CSV text into Excel
Paste the lines into column A, keep the column selected, and go to Data > Text to Columns. Choose Delimited, check Comma, and on the last step set ID columns to Text before you click Finish. Column Manager splits a column the same way across a whole file.
Using Google Sheets instead
Go to File > Import > Upload, pick the CSV, and uncheck Convert text to numbers, dates, and formulas so IDs and leading zeros stay as they are. See how to import a CSV into Google Sheets.
CSV to Excel skips all of that: every value goes into the workbook as it is in the CSV, so IDs and leading zeros stay intact, with sized columns and a bold header row. To send the file on, push it to your CRM with the CRM Formatter.
Formatting
What your data looks like in Excel
Every value in your CSV comes through intact, so the workbook matches what you uploaded.
| CSV input | Excel output | Why it matters |
|---|---|---|
| 01234 | 01234 | Leading zeros preserved on ZIPs, SKUs, and account codes. Excel won't silently strip the 0 down to 1234. |
| Leading zeros preserved on ZIPs, SKUs, and account codes. Excel won't silently strip the 0 down to 1234. | ||
| 07123456789 | 07123456789 | UK mobiles and long numeric IDs stay intact. No scientific notation like 7.12E+09 creeping in from Excel's autodetection. |
| UK mobiles and long numeric IDs stay intact. No scientific notation like 7.12E+09 creeping in from Excel's autodetection. | ||
| 45000 | 45000 | Numbers come through as the exact text you uploaded. To total a column with SUM, convert it to numbers in Excel first. |
| Numbers come through as the exact text you uploaded. To total a column with SUM, convert it to numbers in Excel first. | ||
| 2026-01-15 | 2026-01-15 | ISO dates display and sort lexicographically in the right order. Excel won't reformat text cells to '15-Jan-26' or similar. |
| ISO dates display and sort lexicographically in the right order. Excel won't reformat text cells to '15-Jan-26' or similar. | ||
| TRUE | TRUE | Boolean-looking values stay as literal text. Excel won't convert them to a checkbox or a 1/0 numeric. |
| Boolean-looking values stay as literal text. Excel won't convert them to a checkbox or a 1/0 numeric. | ||
| café, über-friendly | café, über-friendly | UTF-8 preserves accents and non-Latin scripts. Commas inside cell values are auto-handled by the CSV parser. |
| UTF-8 preserves accents and non-Latin scripts. Commas inside cell values are auto-handled by the CSV parser. | ||
Headers are bolded. Column widths are sized from the first 100 rows and capped at 50 characters, so a long value doesn't stretch a column across the screen.
The wrong file format might not be the only problem in that file
Upload it and Bridgeant reviews the file before you commit to a tool. It reports what it finds, orders the problems by how much they actually matter, and points you at the tool for each one. That is on every plan including Free, and it works from a summary of your file rather than the contents.
On Starter and up it stops advising and starts doing. Describe the job in a sentence and Bridgeant plans the steps, shows you the plan, and runs them in the right order once you approve. You are not running four jobs by hand and trying to remember which came first.
Bridgeant, the agent inside OperelioPricing
On every plan.
CSV to Excel is on every plan, and so is Excel to CSV, the reverse direction. A larger file is processed up to your plan's row limit, with a banner on the results page saying how many rows were skipped. Row limits: 2,000 on Free, 50,000 on Starter, 75,000 on Pro, 150,000 on Agency. Each run uses one job: 5 a month on Free, 300 on Starter, 1,000 on Pro, 3,000 on Agency. Starter from $29.25 a month, Pro from $74.25, Agency from $224.25, billed annually.
Common questions
CSV to Excel FAQ
How do I open a CSV file in Excel?
Double-click it, or use File > Open, and Excel opens it in a new workbook with its default settings. That's fine for names and short numbers. If the file has IDs, ZIP codes or phone numbers, use Data > From Text/CSV instead and set those columns to Text before you load it.
How do I import a CSV into Excel?
Go to Data > From Text/CSV, pick the file, and click Import. Click Load to put the data on a new sheet, Load To to choose where it goes, or Transform Data to set column types first.
Is CSV to Excel free?
Yes. CSV to Excel is on every plan, including Free, and so is Excel to CSV (the reverse direction). Each run uses one job from your plan's jobs a month. Free covers up to 2,000 rows and 2 MB per file, and paid plans raise both.
Can I open the output in Google Sheets or Numbers?
Yes. The .xlsx output is compatible with Microsoft Excel, Google Sheets, Apple Numbers, and LibreOffice Calc.
Will numbers and dates come through correctly?
Yes. Values come through exactly as they are in the CSV, with leading zeros on IDs preserved and no silent conversion to scientific notation. Because they are stored as text, convert a column to numbers in Excel before totaling it with SUM. ISO-formatted dates display and sort in the right order.
How wide will the columns be?
Column widths are calculated from the actual data (sampled from the first 100 rows). Long values are capped at a readable maximum so columns don't stretch across the screen.
Can the output be a workbook with multiple tabs?
A CSV has no tabs, so the converted output is a one-tab workbook. To turn one list into a multi-tab workbook, run Split File with tabs output instead: it groups rows by a column's values and writes a tab per group.
Is there a row limit?
Free supports up to 2,000 rows per file. Starter supports up to 50,000 rows. Pro supports up to 75,000 rows. Agency supports up to 150,000 rows. File size limits are 2 MB on Free, 25 MB on Starter, 35 MB on Pro, and 100 MB on Agency.
Can I customize the formatting?
The current version applies a standard professional format: bold headers and auto-sized columns. Custom formatting options like colors and borders may be added in a future update.
Does my Excel output have merged cells?
No. Every cell in the CSV becomes an individual cell in Excel. Merged cells are an Excel-only concept; the conversion is one-in, one-out per cell. If you need to merge cells in the output, do it in Excel after downloading.
What happens to blank rows and columns?
Every row and column in your CSV is written to the workbook as-is, including blank cells and blank rows. If you want those trimmed, run Data Health Check's Remove blank rows fix on the CSV first. It's free and uses no job.
How long is my data kept on your servers?
Uploaded files and outputs are retained for 24 hours on Free, 30 days on Starter and Pro, and 90 days on Agency. After that, they are permanently deleted from storage, unless you starred them in your library. On Starter and above you can star a file or delete it yourself at any time from Files.
Can I automate CSV to Excel via an API?
Yes, on the Pro and Agency plans. You get API access to upload files, trigger jobs, and download results programmatically. Pro includes 1,000 API calls per month and Agency 5,000, at 60 requests per minute. An upload through the API can be at most 4.5 MB per request, whatever your plan's file size. On any plan, an AI assistant such as Claude can run it through Operelio's MCP server, which also takes files over 4.5 MB.
Works well with
Want the full walkthrough? Read the CSV to Excel guide →
Stop formatting spreadsheets by hand.
Upload your CSV, get a formatted Excel workbook back. On every plan.