XLSX to CSV

How it works

Choose your file in the box: besides .xlsx and .xlsm, the older .xls format and LibreOffice's .ods are read as well. Pick the delimiter, the sheets to convert and the date and number notation, then press the convert button. The tool opens the workbook inside your browser and reads the cells one by one. For a cell holding a formula it is not the formula that comes across but the result the spreadsheet program calculated last and stored in the file. Dates sit in the file as numbers; the tool looks at the cell format and writes them in the notation you chose — the default follows the language of this page, because the order of a date is a local rule rather than a translation. With "every sheet" each sheet downloads as its own CSV and its name goes into the file name: budget.xlsx gives budget-January.csv, budget-February.csv. Empty cells keep their place: if columns A and C hold data, the B column stays as an empty field and nothing shifts. A UTF-8 mark is added at the start of the output, because without it Excel shows accented letters incorrectly.

This tool is also known as xlsx to csv, excel to csv, convert xlsx to csv, xls to csv, ods to csv, export every excel sheet to csv, read xlsx online.

What is XLSX?

An XLSX file is a ZIP archive rather than one continuous document. Inside sit XML parts: one for each worksheet, one holding the shared pool of cell strings, one describing the number formats, and a set of relationship files saying which part is which. Any program able to unzip and read XML can therefore read a workbook without Excel installed, which is exactly what this page does. Its predecessor .xls is a binary format with none of that structure and cannot be opened the same way; this tool reads it with a separate reader, so the difference stays invisible to you.

What is CSV?

CSV writes a single table as lines of plain text and keeps only the core of what a workbook holds: the cell values. There is no room in it for a second sheet, a formula, a font, a cell colour, a merged range, a chart or a row height. That poverty is also its reach — accounting packages, databases, statistics tools and almost every import screen accept CSV, and a file written today will still open in software written decades from now.

What is the Excel date serial number?

Excel does not store dates as text. It counts days from 1 January 1900, which it numbers 1, and keeps the time of day as the fraction after the decimal point, so the 01.01.2024 on your screen is really the number 45292 shown through a date format. Two things follow. Any tool reading the raw file sees a number where you see a date, and the only way to tell them apart is the format definition attached to the cell. Excel also treats 1900 as a leap year, which it was not, so serial 60 is a day that never existed.

What is the difference between XLSX and CSV?

A workbook is an application file: several sheets, formulas that recalculate, formatting, charts and notes, all kept as separate parts inside one package. A CSV is a printout of one table in plain text — no sheets, no formulas, no colour. Converting from the first to the second is therefore a one-way simplification: the data survives, the presentation does not. That is normally what you want when the file is headed for an accounting package, a database or an import screen, and not what you want when a colleague is going to carry on working in it. Size follows from the same fact: the identical table is almost always smaller as a CSV, because nothing in the file is reserved for formatting, formulas or sheet structure.

What comes across, and what cannot

The scope is deliberately narrow, because a CSV is a flat table and a workbook is not. Read the list below before you judge the output: if your file depends on any of these, the loss is in the format, not in the conversion.

Your source file is never modified; a new .csv is produced alongside it. If the data you expected is missing, check which sheet it actually sits on.

• Converted: the text, numbers and dates on the first sheet, plus the last calculated result of every formula
• Converted: .xlsx and .xlsm, plus the older .xls and the .ods files of LibreOffice and OpenOffice
• Converted: every sheet in the workbook — each one becomes its own CSV file, because one CSV holds one table
• Not converted: fonts, colours, merged cells, conditional formatting, column widths
• Not converted: charts, images, comments, macros and pivot tables
• Rejected: password-protected workbooks — the content is encrypted and cannot be read, so remove the password and try again

Which delimiter should you pick?

Pick the one your own Excel expects. Excel reads and writes CSV with the list separator taken from the operating system's regional settings: a comma where the decimal mark is a dot, a semicolon in locales where the comma is the decimal mark. Hand a comma-separated file to an Excel configured for semicolons and every row lands in a single column — nothing is broken, the file is simply being read by the wrong rule.

Choose the comma when the file is going to a program, a database import or a web service rather than to a person: the CSV standard, RFC 4180, is written around the comma and most parsers assume it.

Choose tab when you intend to paste the text straight into a sheet. Both Excel and Google Sheets split tab-separated text into columns as it is pasted.

Dates, formulas and numbers

Excel stores dates as numbers: it counts the days since 1 January 1900 and only shows you a date. This tool reads the cell format, and when it sees a date format it writes the serial number in the notation you picked, adding the time when the cell carries one. The default follows the language of this page, because a date order is a local rule, not a translation: the same day is 03/15/2023 in the United States and 15.03.2023 in much of Europe, and confusing the two corrupts records silently.

Formulas cannot travel to CSV, so the value Excel cached at its last recalculation is used instead. If that calculation was sitting in an error state, the error text in the cell is carried over exactly as it stands.

Numbers come across exactly as they are stored, with a decimal point; that is what a program or a database expects. If you will open the output directly in a spreadsheet that uses the decimal comma, switch the number notation to comma. The third choice, as shown in the spreadsheet, writes what the cell displays: the percent sign, the currency symbol and the rounded digits are kept — good for reading, not for calculating.

Which one should you keep: XLSX or CSV?

Whether the conversion is worth making depends on where the file is going. An XLSX is an application file: formulas recalculate, several sheets sit side by side, formatting survives, and each of those things is a separate XML part inside the package. A CSV is one table written out as plain text — no sheets, no formulas, no colour — and it reads the same in any text editor on any system.

That poverty buys reach. Almost every program accepts a CSV, and the same table takes less room as one, because no space is set aside for formatting, formulas or sheet structure. When data is going into accounting software, a database or an import screen, that is usually exactly what is wanted.

So an XLSX is for working, a CSV is for moving. Keep your source file: this tool writes a new .csv next to it and never changes the workbook, so the formulas and formatting are still there if you need to go back.

• Loading data into accounting or bookkeeping software → CSV
• Importing into a database, a shop backend or a web service → CSV
• Summing, averaging, charting → XLSX
• A report with several sheets → CSV if you want to move the sheets separately, XLSX if you will keep working on them together
• Fonts, colours and merged cells matter → XLSX
• An old or minimal program has to read it → CSV, because plain text needs no support

Frequently asked questions

What happens to a workbook with several sheets?

That is up to you: by default only the first sheet is converted, and with the "every sheet" option each sheet downloads as its own CSV with the sheet name in the file name. The sheets are never merged into one file, because a CSV holds a single table.

Do formulas come across?

Their results do, not the formulas themselves. Excel writes the last calculated value of each formula into the file, so the tool reads that stored value and never has to recalculate anything.

Why do dates sometimes come out as plain numbers?

Excel stores a date as a serial number. This tool looks at the cell format, and when the format says date it writes the number in the notation you chose. If the cell was never formatted, nothing in the file says it is a date, so the raw number comes across.

Can I convert an old .xls file?

Yes. Old .xls files and LibreOffice .ods files are read directly; there is no need to open them in Excel and save them again. The only case that cannot be read is a password-protected file.

Are password-protected workbooks supported?

No. The contents of a protected workbook are encrypted, so there is no readable package inside and the tool stops with an error instead of producing half a file. Remove the password in Excel first.

Is my file uploaded anywhere?

No. Unpacking the archive, reading the XML and writing the CSV all happen inside your browser; the workbook never reaches a server.

Is a CSV file an Excel file?

No. A CSV is a text format Excel can open, which is not the same thing as an Excel file: it holds no sheets, no formulas and no formatting. Open one in Excel, add colours and save, and the file stays a CSV — everything you added is gone when it closes, which is what the warning dialog is telling you. To keep it, use Save As and choose the .xlsx format.