CSV to XLSX Converter

Quick answer: Convert CSV to a real Excel workbook, dodging the encoding and number-format traps of opening CSV directly. Open CSV 转 XLSX — everything runs locally in your browser, and files never leave your device.

Steps

1. Upload the .csv to the CSV to XLSX tool.
2. Confirm separator (comma/semicolon/tab) and encoding (UTF-8).
3. Download the .xlsx and check long-number columns.

Important notes

• Encoding is the mojibake culprit: BOM-less UTF-8 Chinese CSVs open as garbage in Excel — this converter reads UTF-8 correctly.
• ID and phone columns may still display as scientific notation — format the column as Text in Excel.
• Fields containing commas or newlines must be properly quoted or rows will mis-split.

Common questions

Reverse direction? Use the Excel to CSV tool.

Multi-sheet XLSX? This converts one CSV; split an XLSX per sheet first.

Pro tips

The three data-damage traps in CSV-to-Excel are all invisible in the CSV itself: leading zeros (007 becomes 7), long IDs (account numbers become 1.23E+11), and dates (2026-09-13 becomes a locale-dependent serial). If the file will be re-exported or used for lookups, import the dangerous columns as Text — the converter preserves the raw strings when you disable type inference. Also check the row count after conversion: a malformed quote mid-file can silently merge two rows, and a count mismatch is the cheapest early warning.

Why does my multilingual text break? The CSV was not UTF-8 — re-export with UTF-8 encoding, or clean the mojibake with the Encode/Decode tool if re-export is impossible.