MD5 is a hash function that turns any input into a fixed 128-bit value, shown as 32 hexadecimal characters. The same input always produces the same digest, which makes it useful for checksums.

Is MD5 secure for passwords?

No. MD5 is cryptographically broken: collisions can be generated cheaply, so it must never be used for passwords, signatures, or any security-critical purpose. Use bcrypt or Argon2 for passwords instead.

Why does an empty input still produce a hash?

MD5 is defined for any input length including zero bytes. The hash of an empty string is the well-known constant d41d8cd98f00b204e9800998ecf8427e, which confirms the implementation is working.

Is my text sent to a server?

No. The MD5 computation runs entirely in your browser using JavaScript, so the text you enter never leaves your device. The page works even with your network disconnected.

What is MD5 still acceptable for?

MD5 remains fine for non-security uses such as detecting accidental file corruption, deduplicating data, or generating cache keys, where an attacker is not trying to forge a matching input.

MD5 Hash Generator — Gera Tools

What MD5 produces

MD5 takes any text or byte stream and produces a fixed 128-bit value, displayed as 32 hexadecimal characters. The same input always yields the same digest, and a tiny change in the input produces a completely different output. That makes MD5 convenient for checksums, deduplication, and cache keys.

How it works

MD5 processes the message in 512-bit blocks after padding it so its length is congruent to 448 modulo 512, then appending the original 64-bit length. Each block updates four 32-bit state words (A, B, C, D) through 64 operations grouped into four rounds, each using a nonlinear function, a per-step sine-derived constant, and a left-rotate. The final concatenation of the four words, output little-endian, is the digest. This tool implements that full algorithm in JavaScript, so the result matches any standard MD5 library.

Security note and example

The MD5 of an empty string is the recognizable constant d41d8cd98f00b204e9800998ecf8427e, a quick way to confirm the tool is correct. Important: MD5 is cryptographically broken. Practical collision attacks exist, so never use it for passwords, digital signatures, or anything an attacker could try to forge. For passwords use a slow, salted hash such as bcrypt or Argon2; for integrity against adversaries use SHA-256 or stronger. MD5 is only appropriate for non-adversarial checksums.