- Decodes the selected source encoding and writes a new UTF-8 file.
- Can add a UTF-8 BOM for better compatibility with some versions of Excel.
- Preserves the decoded Unicode text shown in the preview.
FIX TOOL · 02
CSV Encoding Fixer
Convert legacy CSV text to UTF-8.
Fix strange characters by decoding Windows-1252, Shift_JIS, UTF-16, or UTF-8 and downloading a compatible UTF-8 CSV.
✓ Free✓ No signup✓ Runs in your browser
Upload a CSV file to convert it
Your data never leaves your browser
Drop a CSV file here
Choose a fileCSV, TSV or text · up to 50 MB
THE PROBLEM
How do I convert a CSV to UTF-8?
CSV files do not reliably declare their character encoding. When Excel, an accounting system, or a database opens Windows-1252 or Shift_JIS bytes as UTF-8, accents and Japanese text turn into question marks or garbled characters.
- Rows, columns, delimiters, and cell values are not cleaned or reorganized.
- The tool does not guess replacements for text that was already permanently corrupted before upload.
- The source file remains untouched.
HOW IT WORKS
Clear changes, no hidden guesses
Why characters break
If one app saves Windows-1252 or Shift_JIS and another assumes UTF-8, the same bytes are interpreted as different characters.
Excel and UTF-8
A UTF-8 BOM can help Excel identify the file correctly without changing the actual data values.
Preserving Japanese text
Shift_JIS detection is a best guess. If the preview is wrong, choose the source encoding yourself before downloading.