CSV to Excel

Spreadsheet ready.

CSV to .xlsx. On-device.

.csv .tsv · tap to browse

or

No upload
Works offline
No tracking

Need to convert large CSV files? The offline bundle handles unlimited files with no limits. $49 once.

Get Bundle →
// How it works

Three steps. Zero uploads.

01
Drop
Drop a CSV file or paste data. It stays on your device.
02
Configure
Set sheet name and auto-detection options.
03
Convert
Download as .xlsx. Nothing was ever uploaded.
// Why this is different

Your data never leaves your machine.

Most online converters upload your CSV to a server. Your data passes through systems you don't control.

fwip works differently. The conversion engine runs entirely in your browser. Your data is read from your device, processed on your CPU, and the result is saved back to your device. No server is involved. We literally cannot see your file.

No server processing

Everything runs on your device using WebAssembly. Your file never touches a network.

No account required

Drop a file. Get a result. No sign-up, no email, no password.

No subscription

Free in the browser. $99 once for the offline bundle. That's it. Forever.

Works offline

The desktop version works with no internet connection at all.

// Questions

Frequently asked.

Does this preserve formatting?▾
fwip creates a clean Excel file with auto-sized columns. Cell formatting like colors and borders are not added — it's a clean data conversion.
Can I convert multiple CSVs to multiple sheets?▾
Currently one CSV per conversion. Each creates a single-sheet workbook. For multiple sheets, convert individually.
What Excel features are supported?▾
Auto-sized columns, number detection, and proper cell types. Formulas, charts, and macros are not generated.
Are numbers preserved correctly?▾
With "Auto-detect numbers" enabled, numeric strings are converted to actual Excel numbers. Disable it to keep everything as text.
What about large CSV files?▾
SheetJS handles files with hundreds of thousands of rows efficiently. The preview shows the first 10 rows for performance.
// Related tools

You might also need.

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Combine multiple CSV files into one.
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Sort CSV data by any column. Multi-column sort.
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Filter CSV
Filter CSV rows by conditions. Contains, regex, more.
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CSV to SQL
Generate SQL INSERT statements from CSV data.

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$15
This tool
  • CSV to Excel · offline
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Complete suite
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