Convert CSV to XLSX
Drop your CSV and get XLSX back in seconds. Our AI handles the conversion — no settings, no software, nothing to learn.
Talk to your files
Anything that used to take five menus and three export dialogs is now one sentence in the chat. Watch it work:
Built for how you actually work
One assistant instead of a dozen single-purpose converter sites.
Every format in one place
Images, documents, video, audio and data — 50+ formats handled by one chat, with a dedicated page for every conversion.
Private by design
Your files are used to run your conversion and nothing else. No sharing, no training, and everything auto-deletes within 24 hours.
Seconds, not minutes
Most conversions come back before you'd have found the right export menu.
Speaks your language
The whole product — pages, assistant and answers — works in seven languages.
Nothing to install
Runs entirely in your browser, on any device. No apps, no accounts to start, no updates.
CSV vs XLSX at a glance
| CSV | XLSX | |
|---|---|---|
| Type | Structured data | Spreadsheet |
| File extension | .csv | .xlsx |
| Support | Opens everywhere | Most apps and devices |
| Best for | Moving tabular data between tools | Spreadsheets with formulas and formatting |
What is a CSV file?
CSV is the lingua franca of tabular data: plain-text rows of comma-separated values that every spreadsheet, database and programming language can read. It holds exactly one sheet, with no formulas or formatting.
What is a XLSX file?
XLSX is Excel's native format: multiple sheets, formulas, charts, formatting and proper data types in one file. Google Sheets, LibreOffice and Numbers all open it too.
Why convert CSV to XLSX?
CSV can't hold multiple sheets, data types, formulas or formatting — and Excel easily mangles its encodings and dates. XLSX opens straight into Excel or Google Sheets with data types, multiple sheets and formatting intact.
Converting CSV to XLSX, in practice
Why convert at all?
CSV is just text with separators — no formatting, no data types, no multiple sheets. Converting to XLSX gives you a real spreadsheet Excel opens instantly and correctly, instead of the guessing game Excel plays when it opens raw CSV.
XLSX also holds up to 1,048,576 rows per sheet. If your CSV exceeds that, it needs splitting first — ask in the chat.
The accents-look-broken problem
If opening your CSV in Excel turns “é” into “é”, the file is UTF-8 but Excel guessed a legacy encoding. Converting to XLSX fixes this permanently, because XLSX stores text with its encoding declared — no guessing on the receiving end.
Commas, semicolons and other separators
European locales often export “CSV” separated by semicolons, and some systems use tabs. If your columns come out merged or split wrong, tell the assistant what the file uses — “this CSV is semicolon-separated” — and convert again.
Check the columns Excel likes to mangle
Excel's type-guessing is notorious: leading zeros vanish from ZIP codes and phone numbers, and anything date-like gets reformatted. After converting, spot-check those columns. If a column must stay exactly as written, mention it in your request so it can be treated as text.
Batch and limits
Attach up to 3 CSVs per message as a guest (25 MB each, 10 conversions per day) or 12 files at up to 100 MB with a free account. Each returns as its own XLSX.
CSV to XLSX, answered
Common questions about converting CSV to XLSX.
Drop your CSV into the chat and ask to convert it to XLSX. The assistant runs the conversion and gives you a XLSX to download — usually in a second or two.
Yes. You can convert CSV to XLSX for free as a guest. Signing in raises your limits and lets you convert more files per day.
No. Everything runs in your browser — there's nothing to download or set up. Just drop your CSV and go.
Your CSV is only used to run the conversion you asked for. We don't share it or use it for anything else, and it's automatically deleted from our servers within 24 hours.
Yes — this one. Drop the CSV in the chat, ask for Excel format, download the XLSX. Free as a guest, no installation or account required.
Excel often misdetects the file's text encoding when opening CSV directly. Converting the CSV to XLSX sidesteps the problem: the spreadsheet stores its encoding explicitly, so accents and special characters display correctly everywhere.
1,048,576 rows per sheet — an Excel format limit, not ours. Larger CSVs need to be split across sheets or files first.