Are hashes reversible?

No. A cryptographic hash is one-way: you cannot recover the original input from its digest. That is why passwords are stored hashed, not in plain text.

MD5 and SHA-1 have known collision weaknesses and must not be used for security. They remain useful for checksums, deduplication and legacy compatibility.

What is HMAC and when do I need it?

HMAC hashes a message together with a secret key, producing a digest that only someone holding the key can recreate. It is used to verify message integrity and authenticity — e.g. signing webhook payloads or API requests.

Is my data sent to a server?

Never. Hashing runs locally with the browser's Web Crypto API and in-page MD5/CRC32 implementations. Files you drop in are read in memory on this device and never uploaded.

Which hash algorithm should I pick?

Use SHA-256 by default for integrity checks and signatures; SHA-512 is equally strong with a longer digest. Use SHA-1 or MD5 only for legacy compatibility or non-security checksums, and never store passwords with a plain fast hash — use bcrypt, scrypt or Argon2 instead.

Hash Generator

Generate MD5, CRC32, SHA-1, SHA-256, SHA-384, SHA-512 and HMAC hashes.

Frequently asked questions

Are hashes reversible?: No. A cryptographic hash is one-way: you cannot recover the original input from its digest. That is why passwords are stored hashed, not in plain text.
Is MD5 secure?: MD5 and SHA-1 have known collision weaknesses and must not be used for security. They remain useful for checksums, deduplication and legacy compatibility.
What is HMAC and when do I need it?: HMAC hashes a message together with a secret key, producing a digest that only someone holding the key can recreate. It is used to verify message integrity and authenticity — e.g. signing webhook payloads or API requests.
Is my data sent to a server?: Never. Hashing runs locally with the browser's Web Crypto API and in-page MD5/CRC32 implementations. Files you drop in are read in memory on this device and never uploaded.
Which hash algorithm should I pick?: Use SHA-256 by default for integrity checks and signatures; SHA-512 is equally strong with a longer digest. Use SHA-1 or MD5 only for legacy compatibility or non-security checksums, and never store passwords with a plain fast hash — use bcrypt, scrypt or Argon2 instead.

About this tool

A hash function turns any input into a fixed-length fingerprint. Hashes are used for file checksums, data integrity checks, deduplication and keyed message authentication (HMAC). This generator computes MD5, CRC32, SHA-1, SHA-256, SHA-384 and SHA-512 for text or files locally, with optional HMAC and hex or base64 output.

How to use it

Type or paste the text to hash, or choose a file — the file replaces the text input.
Optionally enter an HMAC secret key to produce keyed digests instead of plain hashes.
Pick hex or base64 output, and lower or upper case for hex.
Copy one digest from its card, or use Copy result to copy every algorithm at once.

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