Saving an Excel file as CSV should be the easiest task in office software. Yet the results are legendary: names like José arrive as José, ZIP codes lose their leading zeros, half the columns land in the wrong place because of a delimiter mismatch, and — surprise — only one of your workbook's five sheets made it into the file.
None of this is bad luck. Each failure has one specific cause and one specific fix. This guide covers all four classic gotchas — encoding, delimiters, leading zeros, and multi-sheet exports — plus a way to convert .xlsx to CSV with the free Toolyfied Excel to CSV converter without even opening Excel.
Gotcha 1: Garbled Characters — Always Choose CSV UTF-8
If accented letters, currency symbols, or non-Latin scripts turn into gibberish after export, you hit an encoding problem. Excel's plain "CSV (Comma delimited)" format saves in a legacy regional encoding (like Windows-1252), and when another system reads that file expecting UTF-8 — the universal standard virtually every modern app assumes — every non-ASCII character gets mistranslated. That is how José becomes José and € becomes €.
The fix inside Excel is choosing the right entry in the Save As list: "CSV UTF-8 (Comma delimited) (*.csv)", not the plain CSV option a few lines below it. UTF-8 can represent every character in every language, so whatever reads the file next — a web app, a CRM import, a Python script — sees exactly what you saw. If a file has already been garbled, re-export from the original .xlsx; converting the broken CSV again cannot restore the lost characters.
Gotcha 2: Comma vs Semicolon — the Delimiter Mismatch
CSV stands for comma-separated values, but Excel does not always use commas. On systems with European regional settings, the comma is the decimal separator (3,14), so Excel switches the CSV delimiter to a semicolon to avoid ambiguity. Send that semicolon-delimited file to someone expecting commas and their import crams every row into a single field — the mirror image of the CSV opens in one column problem.
Before uploading a CSV anywhere, open it in a text editor and check which character actually separates the values, and check what delimiter the destination system expects. If they disagree, either change your system's list separator (Windows regional settings) before exporting, or use a converter that outputs standard comma-delimited UTF-8 regardless of your machine's locale.
Gotcha 3: Leading Zeros Disappearing from ZIP Codes and IDs
Here is the subtle part: the CSV export usually is not what deletes your leading zeros — Excel deleted them the moment the data was typed or pasted, silently converting 02139 into the number 2139. The CSV just faithfully records the damage. Since CSV has no formatting metadata, there is also nothing in the file to say "this column is text."
Prevention beats repair: format ZIP, phone, and product-code columns as Text (or prefix entries with an apostrophe) before data enters the sheet. If zeros are already gone and the codes should be a fixed width, rebuild them with a formula like TEXT(A2,"00000") in a helper column, then export. And remember the round-trip risk: if you later double-click the CSV, Excel will strip the zeros again on open — reimport it properly instead with the CSV to Excel converter.
Gotcha 4: Only One Sheet Exports — and the Fast Way Around Everything
CSV is a single flat table by definition, so Excel exports only the active sheet and warns you about "features not compatible with CSV." A five-tab workbook needs five exports — click each tab, Save As, new filename, repeat — and it is painfully easy to overwrite one file with another or lose track of which tab you exported.
For a clean conversion without babysitting Excel's dialogs (or without Excel installed at all), use the online route:
- Step 1 — Open the free Excel to CSV converter in any browser — no installation, no sign-up, no watermark.
- Step 2 — Upload your .xlsx or .xls file (up to 50 MB).
- Step 3 — Convert. The output is standard comma-delimited, UTF-8 encoded CSV — no locale surprises, no encoding roulette.
- Step 4 — Download the CSV and verify it in a text editor: check one accented character and one leading-zero value, and you are done.
- Step 5 — Need the data as JSON for an API instead? Feed the fresh CSV straight into the CSV to JSON converter.
