In Excel: open the file via Data ▸ From Text/CSV (not by double-clicking), check the detected delimiter and column types in the preview, then Load — or convert it to a real .xlsx with the tool above.
3 rows · 3 columns · Clean numbers become numeric cells; IDs like 007 stay text.
What this does
A .csv is plain text, not an Excel file — Excel merely knows how to display it. Double-clicking lets Excel guess the delimiter and data types, which is where mangled umlauts, stripped leading zeros, and dates like 1/2 turning into February 1st come from. Importing through Data ▸ From Text/CSV (Power Query) shows a preview where you control the delimiter, encoding, and per-column types before anything is loaded. The same idea underpins a lot of everyday Excel work, so the few minutes spent getting it right here pay back across every sheet you build afterwards. Treat it as a pattern, not a one-off, and it stops being something you look up and starts being something you reach for. The difference between a quick fix and a sheet you can trust is the extra minute you spend validating “change excel csv separator”. Start on a copy or a tiny sample, keep the affected cells visible, and compare the result with the tool above before you touch the real workbook. When this is a ribbon command, the selection matters more than the button: confirm the range, apply the command, then spot-check the output before saving. The point is a data step that keeps your analysis trustworthy, but the practical win is that someone else can open the file and understand what happened without asking you.
A worked example
A bank export orders.csv uses semicolons and contains the customer number 007. Double-clicked, Excel shows 7 in one column on some systems and everything-in-column-A on others. Imported via From Text/CSV with delimiter Semicolon and the customer column set to Text, it loads as 007 in its own column — then File ▸ Save As .xlsx makes it a real workbook. Almost every system exports CSV, and almost every recipient wants a clean spreadsheet. Controlling the import (or converting directly) prevents the classic silent data corruption: lost zeros, wrong dates, broken characters. One habit worth forming early: name the cells that hold your inputs, so the formula reads in plain language instead of a string of cell addresses. A reviewer — or you in three months — can then follow the logic without decoding what B7 and D2 were supposed to mean, which is most of what makes a sheet maintainable.
In Google Sheets
Everything above works in Google Sheets too. Excel and Sheets share the formula syntax used here; only the surrounding menus are arranged differently. That portability is deliberate — learn it once and it follows you between the two tools and across Windows and Mac. Nothing on this page is behind a login: the tool runs entirely in your browser, the formula is shown in full with one-click copy, and the steps work the same on Windows and Mac. That is the whole promise here — the exact answer, a way to prove it on your own numbers, and just enough context to make it stick. Here is the takeaway for “change excel csv separator”: copy the answer if you are busy, but if you have a spare few minutes, rebuild the example in Excel yourself with the tool above open beside it. That single pass — type it, run it, watch the result move when you change an input — is what turns a formula you found into a technique you trust. Keep your inputs labelled and referenced, never hard-coded, and the same sheet stays correct and auditable as it grows. Done that way, you will not need to look this up again, and you will be the person others ask.
Common mistakes
- Double-clicking the CSV and letting Excel guess the delimiter and types.
- Losing leading zeros because numeric-looking IDs were auto-typed as numbers.
- Broken ä/ö/ü because the file is UTF-8 but was read as ANSI — set File Origin to 65001: Unicode (UTF-8).
- Saving the imported data back as .csv and wondering where the formatting went — save as .xlsx.
Frequently asked questions
Is a CSV file an Excel file?
No. CSV is plain text with delimiter-separated values. Excel can open and display it, but features like formulas, formatting, and multiple sheets need .xlsx.
Why does my CSV open with everything in column A?
The file's delimiter does not match your system list separator (comma vs. semicolon). Import via Data ▸ From Text/CSV and set the delimiter explicitly.
Is the converter on this page safe for confidential data?
Yes — it builds the .xlsx entirely in your browser. Nothing is uploaded.