CSV to Excel Converter

The CSV to Excel Converter is a free online tool that convert csv files to real xlsx spreadsheets with typed cells, bold headers, and shared-string optimization. generated via jszip, all in-browser.. It runs entirely in your browser with no installation or sign-up needed.

Genuine Office Open XML (.xlsx) with sharedStrings, typed cells, and styles. Opens natively in Excel, Google Sheets, and LibreOffice.

Numbers stored as Excel number cells (so SUM/AVG work), date-like patterns (YYYY-MM-DD, MM/DD/YYYY) recognized, else shared strings.

No. All CSV parsing and XLSX generation happens in your browser via JSZip.

Yes, the CSV to Excel Converter is 100% free with no registration, no hidden fees, and no usage limits. All processing happens locally in your browser, ensuring complete privacy.

Yes, the CSV to Excel Converter is fully responsive and works on smartphones and tablets. You can use it on any device with a modern web browser -- no app download required.

No account or registration is needed. Simply open the CSV to Excel Converter in your browser and start using it immediately. There are no sign-up walls or usage restrictions.

Simply enter your input in the provided field, adjust any settings to your preference, and the tool will process it instantly. You can then copy the result to your clipboard or download it.

The CSV to Excel Converter works in all modern browsers including Chrome, Firefox, Safari, Edge, and Opera. For the best experience, use the latest version of your preferred browser.

When Excel opens a raw CSV, every value is just text, and it sometimes leaves numbers stored as text instead of numeric cells. That is why a column looks fine but SUM, AVERAGE, and COUNT return zero or ignore rows — you cannot do math on text. The fix is to write each value with the correct cell type when the spreadsheet is built, not after. This converter does exactly that: it inspects every value and stores numbers as genuine numeric cells, so functions work the moment the file opens, with no Text-to-Columns cleanup or manual reformatting. Dates in common patterns are recognised too, and everything else goes into a shared-strings table. Paste or upload your CSV here, keep Auto-detect column types on, and download an XLSX where the math just works.

Leading zeros disappear when a spreadsheet treats a value like 01234 as a number, because numerically 01234 equals 1234. This matters for ZIP codes, phone numbers, product SKUs, and account IDs where every digit counts. The safe approach is to store those columns as text so the spreadsheet preserves them exactly as written. In this converter, simply turn off the Auto-detect column types option: with it off, every cell is written as a plain string, so leading zeros, long numeric IDs, and codes that look numeric stay intact. You lose automatic math on number columns, which is the right trade-off when accuracy of the raw value matters more than calculations. Toggle the setting, check the colour-coded preview to confirm nothing is being read as a number, then download your XLSX with the original values untouched.

Not every file labelled CSV actually uses commas. European exports frequently use semicolons because the comma is a decimal separator there, and database dumps often use tabs or pipes. This converter samples the first few lines of your file and automatically picks the most consistent delimiter from comma, semicolon, tab, or pipe, so you do not have to specify it manually. The detected delimiter is shown right above the preview, letting you confirm the file was read correctly before generating anything. Quoted fields are handled too, so a value like "Smith, John" stays in one cell even when comma is the delimiter, and escaped double quotes are unwrapped properly. Just paste your data or upload the file, glance at the reported delimiter, and the columns will split the way you expect.

A shared-strings table is a standard part of the Office Open XML format that XLSX files use. Instead of writing every piece of text directly into each cell, the workbook stores each unique string once in a central table and has the cells reference it by index. When the same value repeats — a status like "Active", a country name, or a category that appears in thousands of rows — it is stored a single time rather than thousands of times, which keeps the file noticeably smaller and faster to open. This converter builds that table automatically as it assembles the workbook with JSZip, following the real XLSX package structure rather than dumping an HTML table. The result is a genuine spreadsheet that opens natively in Excel, Google Sheets, and LibreOffice. Convert your CSV here and the optimisation happens with no extra steps.

Yes. Before anything is generated, the tool shows a live preview of the first 20 rows alongside quick stats: the total number of data rows, the column count, the detected delimiter, and an estimated file size. Number and date cells are colour-coded in that preview, so you can confirm the type detection looks right — for example, that an ID column is being treated as text rather than a number — before you commit. This catch-it-early step saves you from downloading a file, opening it in Excel, spotting a problem, and starting over. If something looks wrong, toggle the Auto-detect column types or First row as header options and the preview updates immediately. Once the preview matches what you expect, one click produces the XLSX, ready to share or edit. Paste your data above to see the preview now.