SHA256 Hasher: A Browser Tool for Text and Files

Local hashing

This hasher uses the browser Web Crypto API, so text and files are processed on your machine and nothing is transmitted. That is the difference that matters when the input is a config file, an access token or a customer record.

It is also faster for large input than a round trip to a server, since Web Crypto is backed by native code and modern CPUs have SHA instructions.

Details that change the digest

Encoding: text is hashed as UTF-8 bytes. The same characters in UTF-16 give a different digest, which is why a value hashed in a .NET application may not match a value hashed in a shell.

Trailing newlines: we hash exactly the characters you paste. echo "text" | sha256sum appends a newline and will not match; printf %s "text" | sha256sum will.

Whitespace: a trailing space copied along with the input changes everything. If two digests disagree, check the input length before suspecting the tool.

Reading the output

64 hexadecimal characters, always, regardless of input size. Case-insensitive — uppercase and lowercase spell the same 32 bytes. Compare the entire string rather than a prefix.

The digest reveals nothing about the input: not its length, not its type, not whether it was text or a video file. That property is what makes it useful for fingerprinting and useless for storage.