Utilities

Text hash (SHA / MD5)

SHA-256 and SHA-1 via SubtleCrypto; MD5 is computed with a small in-page implementation (for legacy checks only).

Choosing the right digest algorithm

Hashes confirm that data arrived unchanged—release artifacts, config exports, or cache keys. Pick SHA-256 or SHA-512 for new work; reserve MD5 and SHA-1 for systems that still expect them.

Hashes are not encryption

Digests cannot be reversed to recover the original text. If you need confidentiality, encrypt. If you need to store passwords, use a dedicated password hash (bcrypt, Argon2)—not a bare SHA-256 of the plaintext.

Encoding matters

The same phrase hashed as UTF-8 versus Latin-1 yields different digests. When comparing against a third-party checksum, confirm character encoding, newline style, and whether the source included a BOM.

HMAC versus plain hash

API signatures often use HMAC-SHA256 with a secret key, not a naked hash of the body. This tool hashes raw input; replicate the exact signing recipe your provider documents.

FAQ

What is a cryptographic hash?
A one-way function that maps input of any size to a fixed-length fingerprint. The same input always yields the same digest; tiny input changes produce wildly different output.
Is MD5 still safe?
MD5 is broken for collision resistance and should not secure passwords or certificates. It remains useful for non-adversarial checksums and legacy compatibility checks.
Why do two inputs produce the same hash?
That would be a collision. Good algorithms make accidental collisions vanishingly rare; deliberate collisions are the threat against deprecated hashes like MD5 and SHA-1.