Excel to CSV Converter
Drop a .xls or .xlsx, get one CSV — no upload, no signup, ready in seconds.
How to Convert Excel to CSV in Three Steps
Your browser reads the workbook, merges every sheet into one CSV of values, and hands you the download — no app, no upload.
Drop or Pick Your .xls / .xlsx File
Drag a workbook onto the converter, or click to browse. Legacy .xls (Excel 97–2003) and modern .xlsx (Excel 2007+) are read straight from your disk — nothing is sent anywhere. Files up to 100 MB work; larger files are flagged before conversion starts.
Your Browser Writes the CSV
The workbook is parsed with SheetJS entirely in your browser. Every non-empty sheet is concatenated into a single CSV, with a blank row between sheets. Cells are written as their values, not their formulas, in plain UTF-8 with no BOM, comma-delimited.
Download the .csv File
Open the result in Excel, Google Sheets, Numbers, LibreOffice, or any text editor. CSV carries no formulas or formatting, so charts, styles, and macros do not come along — set column formats in your target tool if a value lands as text.
What This Excel to CSV Converter Handles That Excel Won’t
Six capabilities that run entirely in your browser — no signup, no upload, and a few things Excel’s own Save As CSV does not do.
No Server Side — The Workbook Stays On Your Machine
SheetJS runs the whole parse in your browser, so the workbook never travels to a server. There is no upload to disable and no traffic to inspect. The reverse works the same: you can turn a CSV back into an Excel workbook without it leaving your device.
Every Sheet Merged Into One CSV
A multi-sheet workbook becomes a single CSV, not a ZIP of separate files. Each non-empty sheet is converted in order, separated by a blank row; empty sheets are skipped.
Reads .xls and .xlsx
Drop a legacy .xls (Excel 97–2003) or a modern .xlsx (Excel 2007+). Both parse the same way — Office Open XML and the older BIFF container both resolve to plain cell values.
Values, Not Formulas
A cell holding =SUM(A1:A10) is written as the number it computed, not the formula text. CSV has no formula language, so charts, formatting, and macros do not survive — only the values do.
UTF-8 Without a BOM
The output is plain UTF-8 with no byte-order mark. Accented names, Chinese, Japanese, Korean text, and emoji survive — no “?” or mojibake. Google Sheets, Numbers, and current Excel read it cleanly.
Any Browser, Any Device — Nothing to Install
Windows, macOS, Linux, phone, tablet — if it runs a current browser, it runs this converter. No Excel install, no plugin, no setup. On mobile it is the fastest path from an emailed .xlsx to a CSV.
What Is the Difference Between Excel and CSV?
A workbook is built for a person; CSV is built for a machine. XLSX is a container — a ZIP of XML (Office Open XML, ECMA-376 / ISO/IEC 29500) holding types, formulas, formatting, charts, and multiple sheets. CSV is plain text — the CSV format defined in RFC 4180 (October 2005) keeps one row per line and one field per comma, and stops there: no types, no formulas, no formatting. Converting Excel to CSV strips the workbook down to the values a database, API, or script can read.
Multiple Sheets Become One File
For multiple sheets, this converter also departs from Excel: as Microsoft notes, “Save As CSV” saves only the active sheet — here, every non-empty sheet goes into one CSV, separated by a blank row. Do this and more across the full set of in-browser Excel tools.
The BOM Trap: Why a UTF-8 CSV Can Still Come Out Garbled
This is the part most converters skip. Excel does not store an encoding in the file. When you save a sheet as CSV, Excel writes the encoding it assumes for the locale — on older Windows that is often ANSI / Windows-1252, not UTF-8. Open that file on a Mac, in Google Sheets, or in a UTF-8 script and accented letters and CJK text turn into “?” or mojibake. Excel’s “CSV UTF-8” save option fixes this but prepends a 3-byte BOM (EF BB BF). The BOM tells Excel “this is UTF-8,” yet leaks into the first cell of downstream parsers, databases, and import tools that do not expect it. This converter writes plain UTF-8 with no BOM, which Google Sheets, Numbers, current Excel, and any UTF-8 reader open cleanly. On older Windows Excel that defaults to ANSI, do not double-click — import through Data > From Text/CSV and confirm UTF-8.
How XLSX and CSV Stack Up
| CSV | XLSX | |
|---|---|---|
| What it is | Plain text, one row per line | Workbook (ZIP + XML) |
| What it stores | Cell values only | Values, formulas, types, formatting, charts |
| Multiple sheets | One file is one sheet | Many sheets per workbook |
| Encoding | Plain UTF-8, no BOM (this converter) | Implicit, declared inside the XML |
| Best for | Feeding databases, APIs, scripts | Reading, analyzing, presenting |
A modern XLSX worksheet holds up to 1,048,576 rows by 16,384 columns, per Excel’s official specifications. CSV has no such limit in the format itself — the ceiling is whatever the program reading it can handle.
When You Need CSV, Not a Workbook
Six times plain CSV is what the next system actually wants — and why Excel’s Save As CSV falls short.
Database and API Imports
Databases, ETL jobs, and REST APIs want CSV on the way in, not an XLSX they must parse. A BI-tool export becomes load-ready text in one step. If your system returns JSON, you can build Excel from JSON the same way.
CRM and ERP Bulk Imports
Salesforce, SAP, HubSpot, and most CRMs take CSV uploads for contacts, orders, and inventory. A sheet built for humans — merged headers, formulas, multiple tabs — needs flattening into one CSV first.
Bank Statements and Financial Reconciliation
A bank or payment processor exports an .xlsx. Flattening it to CSV keeps leading zeros on reference numbers and strips the formatting that throws off import tools. Once it is CSV, you can reconcile it against another sheet.
A Tool That Only Exports Excel
Some BI tools give you .xlsx and nothing else. Converting to CSV is the universal first step — before you match values across two columns against a second dataset, or hand the file to a script.
On Mobile — “Just Get Me a CSV”
Someone emailed an .xlsx and you are on your phone. Mobile Excel is slow for one-off exports. This converter runs in the mobile browser and hands you a CSV in seconds.
Sharing Data a Non-Technical Tool Can Read
Your colleague does not want an .xlsx with macros and merged cells. They want a plain file their script, notebook, or editor opens without complaints. Convert here and send the CSV.
No Upload Step — So Nothing to “Delete Later”
Upload-based converters have a retention problem: your workbook sits on their server until a scheduled job purges it. This one has no server side. SheetJS parses the workbook and writes the CSV in your browser, so the file is never on a server to begin with — no “256-bit SSL” pipeline and no “deleted after a few hours” promise, because neither exists.
Shut the tab and the workbook is gone — it lived only in memory, on your machine. That is the right model for a payroll sheet, a customer export, or anything under an NDA: privacy is structural, not a retention pledge you have to trust. It is also free, needs no account, and imposes no daily quota.