Convert XLSX to CSV

How to Convert XLSX to CSV — Step by Step

1. 1

   Drop your XLSX file(s) — or pick from your computer

   Up to 10 files at once, 60 MB each. The drop zone accepts .xlsx, .xls, .xlsb, .xlsm, .ods. The file is uploaded over HTTPS and never leaves our processing pipeline; the source is permanently deleted after 24 hours.

2. 2

   Pick the output sheet (or convert all)

   If your workbook has multiple sheets, you can convert just one or pack each sheet as a separate CSV in a downloadable ZIP. The default is the active sheet — usually what you want.

3. 3

   ExcelMaster evaluates formulas to values

   Unlike browser-only converters that ship the raw =VLOOKUP(...) text string into your CSV, ExcelMaster runs the workbook through a real calculation engine. Formula cells become their numeric or text results — exactly what your downstream tool expects.

4. 4

   UTF-8 with BOM is the default encoding

   Excel on Windows opens UTF-8 CSVs as Latin-1 unless they have a BOM. We add the 3-byte BOM by default so Chinese / Japanese / Korean / accented text round-trips cleanly. (Plain UTF-8 is also offered for Linux / pandas pipelines.)

5. 5

   Comma is the default delimiter — but you can pick semicolon, tab, or pipe

   Most US/UK locales use comma. Most German / French / Spanish locales use semicolon (because comma is the decimal separator). Pick whichever your downstream tool expects — wrong choice causes silent column misalignment.

6. 6

   Click Convert — your CSV is ready in seconds

   Single sheet downloads as plain .csv; multi-sheet downloads as a .zip bundle. The download link is single-use and expires in 24 hours.

Prefer to do it in code? Here's the same conversion in Python and JavaScript

ExcelMaster gives you a no-code UI; here's how the equivalent looks if you'd rather automate it. Both snippets handle the same edge cases as the web tool — formulas, merged cells, UTF-8 BOM.

import pandas as pd

# data_only=True returns calculated values, not formulas
df = pd.read_excel(
    'input.xlsx',
    sheet_name=0,
    engine='openpyxl',
)

# UTF-8 with BOM = utf-8-sig — opens correctly in Excel on Windows
df.to_csv(
    'output.csv',
    index=False,
    encoding='utf-8-sig',
    date_format='%Y-%m-%d',
)

conversion.deepContent.xlsx-to-csv.codeSnippets.javascript

XLSX to CSV — Frequently Asked Questions

What is CSV?

CSV, or Comma-Separated Values, is a simple file format used to store tabular data, such as spreadsheets or databases, in plain text. It uses commas to separate values and new lines to denote rows. CSV files are widely used for data exchange between different applications and are easily readable by both humans and machines.