Shift JIS
Japanese character encoding
Shift JIS (also SJIS, MIME name Shift_JIS, known as PCK in Solaris contexts) is a character encoding for the Japanese language, originally developed by the Japanese company ASCII Corporation in conjunction with Microsoft and standardized as JIS X 0208 Appendix 1.
Shift JIS is based on character sets defined within JIS standards JIS X 0201:1997 (for the single-byte characters) and JIS X 0208:1997 (for the double-byte characters).
As of March 2026, 0.05% of surveyed web pages used Shift JIS (actually decoded as its superset Windows-31J encoding), a decline from 1.3% in July 2014. Shift JIS is the third-most declared character encoding for Japanese websites (though in effect it means its superset Windows-31J is used, so it is third-most popular), declared by 1.0% of sites in the .jp domain, while UTF-8 is used by 99.1% of Japanese websites.
Shift JIS is also sometimes used in QR codes, though UTF-8 is often preferred.
Structure
Shift JIS is an extension of the single-byte encoding JIS X 0201:1997, that uses unassigned code points in JIS X 0201 to encode the double-byte JIS X 0208:1997 character set. The lead bytes for the double-byte characters are "shifted" around the 64 halfwidth katakana characters in the single-byte range 0xA1 to 0xDF.
The single-byte characters 0x00 to 0x7F match the ASCII encoding, except for a yen sign (U+00A5) at 0x5C and an overline (U+203E) at 0x7E in place of the ASCII character set's backslash and tilde respectively (these deviations from ASCII align with JIS X 0201). The single-byte characters from 0xA1 to 0xDF map to the half-width katakana characters found in JIS X 0201.
For double-byte characters, the first byte is always in the range 0x81 to 0x9F or the range 0xE0 to 0xEF (these ranges are unassigned in JIS X 0201). If the first byte is odd, the second byte must be in the range 0x40 to 0x9E (but cannot be 0x7F); if the first byte is even, the second byte must in the range 0x9F to 0xFC.
Shift JIS only guarantees that the first byte of two-byte characters will be high-bit-set (0x80–0xFF); the value of the second byte can be either high or low.
Begin with the source’s own compact description: “Shift JIS” is japanese character encoding. The dossier treats that line as a proposition to test through Shift, Japanese and character, not as a finished interpretation.
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The phrase “japanese character encoding” supplies a clear boundary for inquiry. It also exposes the unanswered questions: who defined that boundary, when it became stable and which sources sit outside it.
Named sources, stable identifiers and responsible institutions provide the strongest route from overview to verifiable evidence. The source revision retrieved here is dated Jul 5, 2026. The linked authority identifier is Q286345. None of the 0 selected statements returned an explicit reference. The first chronological checks are 1997, 2026 and 2014.
Overview language is designed for orientation and should not be treated as a substitute for the evidence cited beneath it. The lead is largely declarative, so disagreement and counter-evidence require a deliberate search beyond the opening account. Authority statements aid reconciliation but still require their own references, qualifiers and ranks to be checked.
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This entry incorporates text from “Shift JIS” on English Wikipedia. Contributors are listed in the page history. Text is available under the Creative Commons Attribution-ShareAlike 4.0 License. Selected authority identifiers and statements are retrieved from Wikidata under CC0; their references and qualifiers remain part of the verification path.