You need to get a sheet out of an Excel file and into something a database, a script or an import form will accept. The answer is almost always CSV. This guide covers how to convert a single sheet cleanly, which delimiter to choose, and how to keep numbers and dates from breaking.
The short version: open the workbook, pick the sheet, choose a comma, semicolon or tab delimiter, and download a plain-text CSV. The Excel to CSV converter does this on your device, so nothing is uploaded.
What CSV is, and why so many tools want it
CSV stands for comma-separated values. It is a plain-text file where each line is a row and each value is separated by a delimiter, usually a comma. There are no fonts, no colours, no formulas and no multiple tabs. Just the data.
That plainness is exactly why import systems love it. A database, an analytics tool, a mailing-list importer or a few lines of code can read CSV with almost no effort, while a real .xlsx file is a zipped bundle of XML that needs a dedicated library to open. When a form says “upload a spreadsheet,” CSV is what it is built to handle.
The trade-off is that CSV carries one table and nothing else. A workbook with three sheets becomes three separate CSV files. That is not a limitation to fight; it is the format doing its job.
Choosing the right delimiter
The delimiter is the character that separates one value from the next. You have three sensible choices:
| Delimiter | Use it when |
|---|---|
Comma , | The default. Works with almost every tool and language. |
Semicolon ; | Your data already contains commas, or you are importing in a region where Excel expects semicolons. |
| Tab | A tool specifically asks for TSV (tab-separated values). |
There is one subtlety worth understanding. If a cell contains the delimiter (say a comma inside Smith, John while you are using a comma delimiter), the value has to be wrapped in quotes ("Smith, John") so the column does not split in two. A correct converter does this quoting for you, and also doubles any quote marks already inside a value. That is why exporting through a proper tool beats copying cells into a text file by hand.
How to convert a sheet to CSV
Step 1: Open the workbook
Drop your .xlsx or .xls file into the converter. Every sheet inside it is listed so you can see what you are working with.
Step 2: Pick the sheet and delimiter
Select the sheet you want to export and choose your delimiter. The preview shows the data so you can confirm the columns line up before you download.
Step 3: Download the CSV
Download the file. It is plain text, correctly quoted, and ready to feed into whatever asked for it.
Keeping numbers and dates intact
A common frustration is opening a CSV and finding that a long order number like 100200300400 has turned into 1.002E+11, or that 03-04 became a date. Worth being clear about where that happens: it is Excel reading a CSV, not the conversion writing one.
When you export to CSV here, numbers are written as their plain values and dates in a standard, unambiguous text form. The file on disk is correct. The mangling happens later if you double-click that CSV to open it back in Excel, because Excel guesses types as it imports. If you need to reopen a CSV in Excel without surprises, bring it in through Data → From Text/CSV and set the column types, rather than double-clicking, or convert it to a real workbook first, which is what the CSV to Excel converter is for.
Common mistakes to avoid
- Exporting every sheet into one file. CSV holds one table. Convert sheets one at a time so each file stays clean.
- Using a comma delimiter with comma-heavy data. If your values contain commas, a semicolon delimiter avoids a forest of quote marks and is easier for some tools to read.
- Blaming the export for Excel’s import quirks. If a number or date looks wrong only after you reopen the CSV in Excel, the file is fine. Excel’s import guessing is the culprit.
Need to go the other way and turn a CSV back into a real workbook with typed cells? See how to convert CSV to Excel.