ERROR - Updated 2026-05-15
Japanese CSV Mojibake Fix
How to fix Japanese CSV mojibake caused by Shift-JIS, UTF-8, Excel CSV imports, and encoding mismatches.
Open CSV Encoding FixerQuick Answer
Japanese CSV mojibake happens when a file is decoded with the wrong encoding, most often Shift-JIS versus UTF-8. Excel, Google Sheets, upload forms, and code editors may not make the same guess. Start from the original file, identify the source system, and convert only after the Japanese text previews correctly.
Why This Matters
Japanese product names, addresses, company names, and customer messages often move through CSV files. If mojibake is saved back into the file, the original text can be hard to recover. This is especially common when a Japanese Windows export is opened on another machine or uploaded to a UTF-8-only service.
Common Causes
| Situation | Likely Encoding | What to Try |
|---|---|---|
| Export from Japanese legacy software | Shift-JIS or CP932 | Open with Japanese encoding first |
| Export from a modern SaaS | UTF-8 | Use UTF-8 import or UTF-8 BOM for Excel |
| API export | UTF-8 | Check response charset and documentation |
| Excel handoff | UTF-8 BOM or local encoding | Test on the recipient's Excel |
Practical Workflow
- Do not save the file while it is garbled.
- Check whether the file came from Japanese Windows, Excel, a SaaS export, or an API.
- Preview the file as UTF-8 and Shift-JIS.
- If UTF-8 looks correct but Excel is the problem, create a UTF-8 BOM copy.
- If Shift-JIS looks correct, convert a copy to UTF-8 before uploading to modern systems.
FixData Tool
CSV Encoding Fixer can help inspect a CSV sample and create a UTF-8 BOM version for Excel. Use a small sample when the file contains private customer data.
Example
Mojibake:
company,address
譬ｪ蠑丈ｼ夂､ｾ繧ｵ繝ｳ繝励Ν,譚ｱ莠ｬ驛ｽ
Expected:
company,address
株式会社サンプル,東京都
The fix is not to edit the broken text by hand. Reopen the original with the right encoding, then convert a clean copy.
Common Mistakes
- Saving the CSV after Excel shows mojibake.
- Assuming UTF-8 BOM fixes every Japanese CSV.
- Ignoring CP932/Shift-JIS files from older Japanese systems.
- Uploading an Excel-only copy to an API that rejects BOM.
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Updated
2026-05-15