How do I convert an XLSX file to CSV?

Open the .xlsx file, pick the sheet in the left pane, leave the output on .csv and press Download. The CSV uses commas, CRLF line endings and RFC 4180 quoting unless you change them: a semicolon or vertical bar instead of the comma, quotes around every field, LF line endings, or a UTF-8 byte order mark, which helps Excel read accented letters correctly.

Why does 0012 turn into 12, and how do I keep the zeros?

Spreadsheet programs guess that 0012 is a number and drop the zeros. Here a text cell in an XLSX stays text, and a CSV column is only typed as numbers when every value in it would come back as the same characters, so 0012, 1.50 or a 20-digit ID stays text. Set the column to Number yourself if you do want 12.

What happens to formulas when I convert?

Each formula cell is exported as the value the file last saved, the value Excel showed when the file was saved. Nothing is recalculated. A workbook written by a program that never calculated its formulas has cells with no saved value: those are listed in the left pane and left empty in the output rather than guessed. The formulas themselves are not carried into the new file.

Can I convert CSV to XLSX without =SUM(A1) turning into a formula?

Yes. Open a CSV or TSV file and choose .xlsx. Every cell is written as a value, and text that starts with an equals sign is written as a text cell, so it shows exactly as typed and never runs. Columns of plain numbers, ISO dates such as 2024-03-01 and TRUE or FALSE become numbers, dates and booleans unless you set them to Text.

What does Formula safety do?

A spreadsheet opening a CSV may run a field that starts with =, +, -, @, a tab or a carriage return as a formula. With Formula safety on, those text fields are written with a leading apostrophe, so a spreadsheet opening the file treats them as text instead of running them. It is off until you turn it on, it leaves plain numbers such as -5 alone, and a CSV read here with the setting on has the apostrophe taken off again, so nothing is lost.

Does it open .xls, .xlsb or .ods files?

No. Those formats are refused with a message naming what the file is: save it as .xlsx or CSV from Excel, LibreOffice or Google Sheets first. A password-protected .xlsx is refused the same way.

Why do some characters print as question marks in the PDF?

The PDF uses the Helvetica font built into every PDF reader, which covers Western European text. Characters outside it, such as Chinese, Hindi or emoji, print as a question mark and the page says how many; the CSV, TSV and XLSX keep them.

How large a file can it convert?

A sheet may spread over at most 10,000,000 cells, empty cells inside the table included, and a PDF stops at 1,000 pages. An XLSX written here keeps to Excel's own limits of 1,048,576 rows and 16,384 columns. The file is read on your device, so a large workbook takes a few seconds and the time depends on your computer. Copy refuses a table longer than 536,870,888 characters as CSV or TSV text, the longest string Chrome and Edge can build, and Download still writes it whole as a .csv or .tsv file.

XLSX to CSV Converter

Open an .xlsx, .csv or .tsv file and the left pane shows what it holds before anything is written: the sheets, the table's range, each column's type as found and the type it will be written as, and the formulas that have no saved value. Choose CSV, TSV, XLSX or PDF and the right pane previews the output from the same code that writes the file. Codes such as 0012 stay text instead of becoming 12, a cell reading =not-a-formula stays text, and quoted commas and line breaks come back identical. The file is read on your device and never uploaded.

No file

Sheets, columns and formulas appear here.

Outputcomma, UTF-8

The converted file appears here.

formula safety off

Open an XLSX, CSV or TSV file

Or drop one here, or

Nothing is uploadedFormulas are never runNo account, no sign-up

Sheet

none open

Table

none open

Formula cells

none open

PDF

Letter portrait

Header row

Read CSV as

Delimiter

Quotes

Line ends

Byte order mark

Formula safety

No file open. Open an XLSX, CSV or TSV file, or the example workbook.

SKU 0012, a text cellCSV to XLSX, then read back
0012 as text, never the number 12
=not-a-formula in a CSV cellconverted to XLSX
a text cell reading =not-a-formula, never a formula
"Bolt, M6" and a two-line cellCSV out, then read back in
quoted on the way out, identical on the way back

Accuracy. Formula cells export the value the file last saved, not a fresh calculation, and a formula with no saved value is listed and left empty rather than guessed. Text such as 0012 or =not-a-formula stays text unless you change its column type. Only cell values move between formats: styles, merged cells, charts and comments are named on screen, not carried.

Common questions

How do I convert an XLSX file to CSV?: Open the .xlsx file, pick the sheet in the left pane, leave the output on .csv and press Download. The CSV uses commas, CRLF line endings and RFC 4180 quoting unless you change them: a semicolon or vertical bar instead of the comma, quotes around every field, LF line endings, or a UTF-8 byte order mark, which helps Excel read accented letters correctly.
Why does 0012 turn into 12, and how do I keep the zeros?: Spreadsheet programs guess that 0012 is a number and drop the zeros. Here a text cell in an XLSX stays text, and a CSV column is only typed as numbers when every value in it would come back as the same characters, so 0012, 1.50 or a 20-digit ID stays text. Set the column to Number yourself if you do want 12.
What happens to formulas when I convert?: Each formula cell is exported as the value the file last saved, the value Excel showed when the file was saved. Nothing is recalculated. A workbook written by a program that never calculated its formulas has cells with no saved value: those are listed in the left pane and left empty in the output rather than guessed. The formulas themselves are not carried into the new file.
Can I convert CSV to XLSX without =SUM(A1) turning into a formula?: Yes. Open a CSV or TSV file and choose .xlsx. Every cell is written as a value, and text that starts with an equals sign is written as a text cell, so it shows exactly as typed and never runs. Columns of plain numbers, ISO dates such as 2024-03-01 and TRUE or FALSE become numbers, dates and booleans unless you set them to Text.
What does Formula safety do?: A spreadsheet opening a CSV may run a field that starts with =, +, -, @, a tab or a carriage return as a formula. With Formula safety on, those text fields are written with a leading apostrophe, so a spreadsheet opening the file treats them as text instead of running them. It is off until you turn it on, it leaves plain numbers such as -5 alone, and a CSV read here with the setting on has the apostrophe taken off again, so nothing is lost.
Does it open .xls, .xlsb or .ods files?: No. Those formats are refused with a message naming what the file is: save it as .xlsx or CSV from Excel, LibreOffice or Google Sheets first. A password-protected .xlsx is refused the same way.
Why do some characters print as question marks in the PDF?: The PDF uses the Helvetica font built into every PDF reader, which covers Western European text. Characters outside it, such as Chinese, Hindi or emoji, print as a question mark and the page says how many; the CSV, TSV and XLSX keep them.
How large a file can it convert?: A sheet may spread over at most 10,000,000 cells, empty cells inside the table included, and a PDF stops at 1,000 pages. An XLSX written here keeps to Excel's own limits of 1,048,576 rows and 16,384 columns. The file is read on your device, so a large workbook takes a few seconds and the time depends on your computer. Copy refuses a table longer than 536,870,888 characters as CSV or TSV text, the longest string Chrome and Edge can build, and Download still writes it whole as a .csv or .tsv file.

Formula cells export the value the file last saved, not a fresh calculation, and a formula with no saved value is listed and left empty rather than guessed. Text such as 0012 or =not-a-formula stays text unless you change its column type. Only cell values move between formats: styles, merged cells, charts and comments are named on screen, not carried.