CSV ⇄ Excel Converter
Turn a CSV file into an Excel workbook without losing leading zeros or long IDs, or export the first sheet of a workbook back to CSV. Files of up to 200MB never leave your browser.
Or convert a .csv file directly — supports files up to 200MB
Drag & drop a file here, or click to browse
Processed in the background, so the page stays responsive even for huge files
How to use this tool
Choose a direction with the toggle. For CSV → Excel, paste your CSV or upload a file directly to download a ready-to-open .xlsx file. For Excel → CSV, drop in a workbook and the first sheet is converted to plain CSV text you can copy or download. Files up to 200MB are supported — uploads run in a background Web Worker so the page never freezes, and files are parsed entirely in your browser — nothing is sent to a server.
How each CSV value becomes an Excel cell
A CSV file has no types: every value is text. When it becomes a workbook, each cell is given a type by these rules, which are designed to keep codes and IDs exactly as written:
1200,-3.5and1,200become numbers, so SUM and charts work straight away.004102(leading zero) and12345678901234567890(more than 15 digits) stay text, all digits kept.2026-03-04and2026-03-04 14:30become real Excel dates, shown as yyyy-mm-dd.TRUEandFALSEbecome Excel booleans.- Everything else, such as
₹499,+91 98765 43210or03/04/2026, stays text exactly as written.
Dates written as 03/04/2026 are deliberately left alone: whether that is 3 April or March 4 depends on where the file came from, and guessing wrong silently corrupts every row.
What Excel → CSV writes
Each cell is written as it appears in Excel, so a currency-formatted 1,200.50 is written as "1,200.50" (quoted, because of the comma). Two deliberate exceptions make the CSV safer for the next system: date cells are written as 2026-09-24 instead of Excel's US-style default 9/24/26, and plain numbers keep every digit (123456789012, not 1.23457E+11). If the next system needs raw numbers without thousands separators, set those columns to General in Excel before converting.
Non-English text and the ₹ sign
Files are read as UTF-8, so Hindi, Gujarati, accented names and the ₹ symbol come through the CSV → Excel direction intact. The CSV this tool writes is UTF-8 too. If Excel on Windows shows garbled characters (₹ instead of ₹) when you double-click that CSV, import it instead: Data → From Text/CSV, with File Origin set to 65001: Unicode (UTF-8). The CSV and XML to Excel guide walks through a full example.
Frequently Asked Questions
Will PIN codes and IDs keep their leading zeros?
Yes. A value with a leading zero such as 004102 is stored in the .xlsx as text, exactly as written, and so is any number longer than 15 digits (Excel can only store 15 significant digits exactly). Double-clicking the same CSV to open it in Excel would turn 004102 into 4102.
My CSV uses semicolons or tabs instead of commas. Does that work?
Yes. The delimiter is detected automatically, so semicolon-separated exports (common from systems set to a European locale), tab-separated and pipe-separated files convert without any setting. Quoted fields that contain the delimiter or a line break stay in one cell.
Which sheet is exported when converting Excel to CSV?
The first sheet of the workbook. If the data you need is on another sheet, move it to the front in Excel before converting. Formula cells are written as the value Excel last calculated and saved, not as the formula.
Why does Excel show a small green triangle in some cells?
That is Excel flagging "number stored as text". It appears on cells such as 004102 that were deliberately kept as text to preserve leading zeros. Codes like PIN codes and account numbers should not be summed anyway, so it is safe to ignore, or you can hide it via Error Checking options.
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