MD5 Hash Generator

This MD5 hash generator turns text or a selected file into the 128-bit message digest defined by RFC 1321 and renders it as 32 hexadecimal characters. Text is converted to UTF-8 bytes; file mode hashes the file bytes. Lowercase and uppercase are display choices for the same digest. The calculation runs in browser code, so the hashing flow requires no server upload.

For the exact three-character input abc—without quotation marks, spaces, or a trailing line break—the result is 900150983cd24fb0d6963f7d28e17f72. RFC 1321 publishes this test vector. Uppercase display changes only the representation, not the digest bits.

For a file checksum, select a file and compare all 32 hexadecimal characters with an expected value. A mismatch proves the file bytes differ from those used for the expected digest. A match can support accidental-error detection, but the source of the expected value matters and an MD5 match is not proof against deliberate substitution.

This is an MD5 generator, not an MD5 decrypt or reverse-hash service. Hashing is not encryption, and a fixed-size digest does not contain a reversible copy of the input. Attempts to reverse a digest normally guess candidate inputs and hash each candidate for comparison.

RFC 6151 states that MD5 is no longer acceptable when collision resistance is required, including digital signatures. Do not rely on MD5 to detect deliberate tampering. The RFC allows an MD5 checksum used solely to protect against errors, but applications must state what security service, if any, they expect from it.

Browser-side calculation reduces the need to transmit text or files for hashing, but it does not make MD5 cryptographically safe. Avoid entering passwords or other secrets into an online hash page.