SM3 hash
Compute a SM3 digest of any file, on your device.
Runs on your device. The file is never uploaded.
SM3 hash turns a file into 256 bits, 64 lowercase hex characters, from the Chinese standard GM/T 0004-2012 that accompanies SM2 and SM4. Every file dropped returns its own two-line result. It is not SHA-256 renamed: the compression function differs, the digest differs, and nothing here converts between the two.
Questions
What is SM3?
The Chinese national cryptographic hash standard, published as GM/T 0004-2012 and used alongside the SM2 signature and SM4 cipher algorithms. It produces a 256-bit digest and turns up in Chinese compliance and government contexts and in software that has to interoperate with them.
How long is the digest?
256 bits, printed as 64 lowercase hex characters, on the line after the title and your file name. There is nothing to configure. It is the same length as a SHA-256 digest and an entirely different value, so never treat one as a substitute for the other when comparing.
Is SM3 the same as SHA-256 with another name?
No. It is a different design with its own compression function, and the same file produces a completely different digest. They share only an output size of 256 bits, so a value from one will never verify against the other. If a document says SM3, compute SM3 rather than substituting SHA-256.
Do I need SM3?
Only if something asks for it. If a Chinese standard, a certificate profile, a payment specification or a counterpart requires SM3, this is where you compute it offline. Otherwise SHA-256 has far broader tooling support and is the easier default, and nothing here suggests switching to SM3 by preference.
Does the file get uploaded?
No. SM3 here comes from hash-wasm, a WebAssembly build running in a Web Worker in this tab, and your file never leaves the device. Drop as many files as you like and each gets its own digest. There is no account, and the page works offline after your first visit.