Hash Generator

A cryptographic hash function consumes bytes and produces a fixed-size digest. SHA-256 always returns 256 bits, whether the input is an empty string, a short identifier, or a long document. Hexadecimal displays four bits per character, so a SHA-256 digest contains 64 hex characters. Base64 is a more compact representation of the same 32 digest bytes; changing the output encoding does not change the underlying hash.

Text must become bytes before it can be hashed. LiveParse encodes the current textarea value as UTF-8. That choice matters for Korean text, emoji, accented characters, and every non-ASCII code point. Browser textarea and paste handling can normalize original CR or CRLF line endings to LF before hashing. Use file mode when original newline bytes must be preserved, and establish an explicit canonicalization rule when several systems must reproduce one value.

Hashing is deliberately one-way: there is no general operation that reconstructs the source from its digest. It is still possible to guess low-entropy inputs by hashing candidates, so a digest is not a safe way to conceal a short secret. Treat hashes as comparison values, not encrypted text.

The interactive workspace accepts at most 5,000,000 UTF-16 code units in text mode. File mode accepts at most 64 MiB and reads the complete selected file into browser memory before calculating its digest. It does not stream chunks, so use a native streaming tool for larger files or repeated batch work.

If two independently obtained digests match, it is strong evidence that the compared byte sequences are identical when a modern collision-resistant algorithm such as SHA-256 is used. This is useful for detecting download corruption, comparing build artifacts, identifying cached content, and checking whether data changed. Always compare the complete digest with an exact, case-insensitive hex parser or decoded bytes rather than a visually shortened prefix.

An ordinary hash has no secret key and no publisher identity. Anyone can compute a new digest after changing the data. If a website, mirror, or network attacker can replace both a file and the checksum displayed beside it, the matching values do not establish an authentic origin. Obtain the expected digest through a trusted channel or verify a digital signature. Use HMAC with a secret key for message authentication between parties that share that key.

Passwords need a different design again. Fast hashes let an attacker test guesses extremely quickly after a database leak. Use a password-specific KDF such as Argon2id, scrypt, bcrypt, or PBKDF2 with a unique random salt, calibrated cost parameters, safe storage, and an upgrade strategy.