What is the difference between GB2312 and GBK?

GB2312 is the original 1980 standard covering common Simplified Chinese characters. GBK is a backward-compatible superset that adds thousands more characters. Any GB2312 byte sequence is valid GBK, so this tool uses the wider GBK table for both directions.

How many bytes per character?

ASCII characters take one byte (0x00 to 0x7F). Each Chinese character takes two bytes: a lead byte from 0x81 to 0xFE and a trail byte from 0x40 to 0xFE, excluding 0x7F. The two-byte form is how GBK packs the large character set.

Why might a character be unmapped?

GBK covers Simplified Chinese and ASCII. Traditional-only characters not shared with the set, emoji, and non-Chinese scripts have no GBK bytes and are flagged with ?? on encoding so you can see what was dropped.

Is GBK the same as Big5?

No. Big5 encodes Traditional Chinese with a different layout; GBK encodes Simplified Chinese. The same character usually has different bytes in each, so always store the encoding name alongside the bytes.

Does the conversion run locally?

Yes. The GBK table is built in your browser from the native decoder and applied locally for both encoding and decoding. No text is uploaded to a server.

GB2312 / GBK Encoder/Decoder

GB2312 and its backward-compatible superset GBK are the standard legacy encodings for Simplified Chinese on the mainland. ASCII stays single-byte while each Chinese character is stored as a two-byte sequence. This tool encodes Simplified Chinese text into GBK hex bytes and decodes GBK bytes back into text, using the wider GBK table so GB2312 data round-trips too.

How it works

ASCII characters 0x00–0x7F are one byte. Each Chinese character is two bytes: a lead byte in 0x81–0xFE followed by a trail byte in 0x40–0xFE (skipping 0x7F). GB2312 occupies a subset of this space, and GBK fills in the rest, which is why a single GBK decoder handles both.

To stay faithful to the real table, the tool enumerates the single-byte range and every valid lead/trail pair, decodes each with the browser’s native GBK decoder, and builds a character-to-bytes map. Encoding looks each character up in that map; decoding runs the hex bytes through the native decoder.

Example and notes

"中文" encodes to d6 d0 ce c4 — two characters, each a two-byte pair, with 中 as D6 D0 and 文 as CE C4.
GBK targets Simplified Chinese; Traditional-only characters and symbols outside the set are flagged as unmapped.
For text that mixes scripts or needs emoji and rare characters, UTF-8 is the modern choice; GBK remains useful for interoperating with legacy Chinese files and systems.