Convert a text file to Shift-JIS

Convert a text file to Shift-JIS (CP932 / Windows-31J). The source encoding is detected for you. For opening a CSV in Japanese Excel, or handing data to a legacy system that accepts nothing else. No installation, done in seconds.

Drag & drop a file here, or click to browse

Accepts: .txt, .csv, .tsv, .md, .json, .xml, .html, .htm, .log, .sql, .yml, .yaml, .ini, .srt, .vtt

When this helps

Anyone opening a CSV in Excel

A UTF-8 CSV opens as garbage in Excel even though the file is perfectly fine.

Convert it to Shift-JIS and Excel opens it correctly on a double-click.

Developers

A client's legacy system only accepts Shift-JIS uploads.

Convert the UTF-8 export to Shift-JIS before sending it on.

Back-office system owners

Import files for the core system have to arrive in a specified encoding.

Whatever encoding a file turns up in, normalise it to Shift-JIS before the import.

FAQ

Will this fix a CSV that garbles in Excel?
Yes. Japanese editions of Excel read a CSV without a byte order mark as Shift-JIS (CP932), so a valid UTF-8 file still opens as garbage. Convert it here and Excel opens it on a double-click, with no trip through the text import wizard.
What happens to characters Shift-JIS doesn't have?
They are replaced with the closest equivalent, and only what has no equivalent at all becomes "?". The é in café becomes e, an em dash becomes ―, € becomes EUR. Emoji, Hangul and simplified-only Chinese characters have nothing to map to and become "?". Both lists are shown with your result, so you always see exactly what changed.
Do circled numbers (①②) and rare kanji (髙) survive?
Yes. Shift-JIS as used here (CP932 / Windows-31J) includes the NEC and IBM extended characters, so ①②⑳, Ⅲ, 髙, 〜, ㈱, №, ℡, ㎡ and ㍻ all convert unchanged. The replacements are mostly accented Western European letters and a few typographic symbols.
Do I have to know the source encoding?
No — detection is the default, covering UTF-8, UTF-16, EUC-JP, ISO-2022-JP, and Chinese, Korean and Cyrillic encodings. The "Source encoding" list is there for the rare case where detection gets it wrong.
Are line endings changed?
No. CRLF stays CRLF and LF stays LF — this tool changes the character encoding and nothing else.
Is my file saved to your server?
No — if your browser supports WebAssembly (WASM, a technology that runs software safely and quickly right inside your browser), the file never leaves your device. If that isn't available, it falls back to normal server-side processing, which holds the file only while it is being converted and deletes it the moment it has been — nothing is kept either way.
What's the file size limit?
10MB per file.

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