PREFLIGHT CHECK
Check whether a Mercari Shops CSV decodes cleanly as Shift_JIS or UTF-8 before upload.
Analysis stays in your browser; the file itself is not sent to BlueprintLab.
| Severity | Row | Column | Issue | Value |
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Live service-side state, account-specific settings, remote server reachability and current master data are not asserted. Always prefer the latest official service information.
Check whether the CSV can be read cleanly as UTF-8, UTF-8 BOM, or Shift_JIS.
商品名,商品説明 テスト商品,サンプル説明
Mercari Shops documents downloaded CSVs as S-JIS on Windows and UTF-8 on non-Windows systems. A file that looks garbled in one app is not automatically corrupt.
This checker verifies whether the file can be interpreted as UTF-8, UTF-8 with BOM, or Shift_JIS.
BOM stands for Byte Order Mark. In UTF-8 files it is commonly used as an encoding signature, and this checker treats UTF-8 BOM as part of the UTF-8 family.
Different spreadsheet apps can display the same bytes differently, so avoid converting the file blindly just because one opening method looks wrong.
An encoding conversion can fix display problems while creating another issue if some characters cannot be represented in the target encoding. Work on a copy and keep the original CSV for comparison.
The CSV mojibake Quick Guide walks through the general diagnosis.
A clean encoding does not rule out quoting, column-count or prohibited-space problems.
Use the Mercari Shops product CSV preflight checker for the broader import structure.