FREE WEB TOOL

Check CSV Mojibake and Unsupported Character Risks

Find unsupported and control characters that may cause garbled CSV text.

Check character risks

This is a risk scan, not a complete Shift_JIS compatibility guarantee.

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How to use it

Before sending CSV to a legacy or Shift_JIS-style import, scan for emoji and other characters that commonly cause mojibake, replacement characters, or data loss. Findings include row/column position and the Unicode code point.

Paste the CSV or text you plan to send.
Review each flagged character, its location, and U+... value.
Compare the findings with the destination system’s documented encoding and decide any replacement in the source data.

“It displays in UTF-8” does not mean every destination can store it

Modern browsers can show characters that an older Shift_JIS-oriented system cannot represent. The risk often appears only at import or export time.

This is a representative risk scan, not a complete encoding proof

The checker looks for common high-risk groups such as supplementary-plane characters, circled numbers, Roman numerals, and certain compatibility/unit symbols. It does not prove that every character is encodable in a particular Shift_JIS implementation.

“Shift_JIS” can mean different practical character sets

Standard Shift_JIS and Windows-31J/CP932 do not have identical repertoires. Some systems say “Shift_JIS” while actually expecting CP932. The receiving system’s real specification is the final authority.

Flagged characters are not automatically replaced

Changing ① to (1) or deleting an emoji may alter meaning. The tool identifies where the risk is; replacement policy belongs to the data owner or receiving-system rules.

A practical example

Scan product names or customer notes before uploading them to a legacy system. A zero-result scan reduces obvious risk but still does not replace a real import test for critical data.

If you want the deeper picture