PTBox

MD5 / SHA Online Hash Calculator

Compute MD5 / SHA-1 / SHA-256 / SHA-384 / SHA-512 hashes locally in the browser. SHA family uses Web Crypto API; MD5 uses js-md5. Inputs are never uploaded.

Usage

Hash functions map arbitrary input to fixed-length output. This tool computes MD5 / SHA-1 / SHA-256 / SHA-384 / SHA-512 in parallel. SHA family uses the browser's crypto.subtle.digest; MD5 uses js-md5 locally.

MD5 and SHA-1 are collision-broken and should not be used for cryptographic purposes; they remain fine for file integrity, cache keys and similar non-adversarial fingerprints. Use SHA-256 or stronger for security.

Use cases

File integrity check

Compare a downloaded file's SHA-256 against the official value to detect tampering.

Cache key generation

Hash request parameters into a stable Redis / local cache key.

Git / blockchain internals

Git objects are addressed by SHA-1; Bitcoin uses SHA-256.

Content deduplication

Detect whether two pieces of content are identical without byte-by-byte comparison.

FAQ

Is MD5 still usable?

Not for cryptography (collisions found), but it's still fine for file integrity, cache keys and ETag — non-adversarial use cases.

Can a hash be reversed?

Not in general, but short or weak inputs can be cracked via rainbow tables. Never hash passwords with plain SHA — use bcrypt / scrypt / argon2.

How much does the output change for a 1-bit input change?

Avalanche effect — about half the output bits flip. The two hashes look completely unrelated.

Can it handle large files?

As long as browser memory allows — a few hundred MB works. For very large files use command-line tools like sha256sum.

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