CSV to Excel
A proper .xlsx from your CSV, written on your device.
Drop files here
or click to choose from your deviceAccepted: CSV, TSV, TXT
Up to 3 files per runUp to 20 MB per file5 runs per dayRemove limits with Pro✓ Works offline
Your files stay on your device
This tool runs entirely in your browser. Nothing is uploaded, nothing is stored, and you can even turn off your internet connection before you start.
Example
An order export with ZIP codes, SKUs and sizes like 3-4: what Excel changes and what stays
A small online shop downloads orders-october.csv: order number, date, ZIP code, phone, SKU, size, quantity, total and a 20-digit tracking number. Opened straight in Excel, the ZIP code 02134 loses its zero. Converted here with the default settings, the .xlsx keeps each cell as written unless it is plainly a figure.
- Drop orders-october.csv and press Convert to Excel. It is comma-separated with a dot for decimals, which “Work it out from the file” finds on its own.
- One ZIP code (02134) and one SKU (00731) start with a zero, so those whole columns stay text — 90210 and 10422 too — and each column sorts as one.
- Three monthly exports at once? Choose “One workbook, a sheet per file”: each CSV becomes a sheet named after its file, in one .xlsx named after the first.
| In the CSV | Opened directly in Excel | In the .xlsx from this page |
|---|---|---|
| ZIP 02134 | 2134 | 02134 (text) |
| SKU 00731 | 731 | 00731 (text) |
| Size 3-4 | 4-Mar (a date) | 3-4 (text) |
| Size 1/2 | 2-Jan (a date) | 1/2 (text) |
| Total "$1,250.75" | 1250.75 | 1250.75 (number) |
| Refund (5.00) | -5 | -5 (number) |
| Tracking 92001903456789012345 | 9.2002E+19, the last digits lost | 92001903456789012345 (text) |
| Date 10/03/2026 | a date | 10/03/2026 (text, as typed) |
orders-october.xlsx has the totals as real numbers you can add up (1250.75, -5, 3980), and every code, size and tracking number exactly as in the CSV. Dates stay as typed; to sort by date, format that column as a date in Excel.
How it works
- Drop the CSV files. Tab-separated files work too.
- Leave the separator on “Work it out from the file” unless a file is unusual — a European CSV using semicolons is recognised on its own.
- Choose whether several files become one workbook with a sheet each, which is the point of dropping a folder of them at once.
- Press Convert to Excel and download the .xlsx.
Frequently asked questions
- Why not just open the CSV in Excel?
- Because Excel changes things on the way in. It reads 007 as 7, turns 3-4 into a date, and mangles anything not saved in the codepage it expects — the usual reason a list of product codes or Japanese names comes out wrong. Converting here writes the cells as they are, and only makes a cell numeric when it is plainly a figure.
- Is my file uploaded?
- No. The CSV is parsed and the workbook written in your browser. A customer list or an export from an internal system stays where it is.
- What decides which cells become numbers?
- A cell that is plainly a figure: 1250, 3.50, -4, 1,250 and $1,250.75 come across as numbers, and a figure in brackets becomes a negative, as an accountant writes it. A file separated by semicolons, or one with figures like 1.250,75, is read the European way, so 3,50 becomes three and a half. Codes that start with a zero (007, a postcode, a phone number), numbers longer than 15 digits, dates, percentages and anything with letters stay as text, because Excel would drop the zero or round the digits. Switch the option off to keep every cell exactly as written.
- Does it handle quoted commas and line breaks inside a cell?
- Yes. The parser follows the CSV convention properly: a value in quotes may contain the separator, quotes doubled inside it, and line breaks. A byte-order mark in front of the file — which Excel itself writes — is dropped rather than becoming part of the first heading.
- What about accented or Japanese characters?
- They come through. A UTF-8 CSV, which is what nearly everything writes today, is read as it is. One that is not valid UTF-8 is read in the older encoding it most likely uses, the same guess Convert encoding makes: Windows-1252 for Western European text, Shift_JIS or EUC-JP for Japanese, EUC-KR (CP949) for Korean. UTF-16 with a byte-order mark works too.
- Can I combine several CSV files into one Excel workbook?
- Yes: choose “One workbook, a sheet per file”. Each CSV becomes a sheet named after its file, and the workbook takes the first file’s name — three monthly exports become one .xlsx with three sheets. The free plan takes three files a run. To go the other way, Excel to CSV writes one CSV per sheet.
- What are the free limits?
- Three files a run at 20 MB each and 5 runs a day. The workbook carries nothing added.
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