What it does
This tool calculates the MD5 hash of any text. MD5 is a cryptographic hash function designed in 1992 by Ronald Rivest. It turns input of any length into a fixed 128-bit value, shown as 32 hexadecimal characters. The same input always gives the same hash, and changing a single character changes the hash completely.
How to use
- Type or paste text into the input box, drop a text file on it, or press Sample.
- The MD5 hash appears as you type.
- Choose Hex or Base64 output, and turn on Uppercase hex if the system you’re comparing with uses capital letters.
- Turn on Hash each line separately to hash a list, such as many passwords or IDs, in one go. Each line gets its own hash on the matching output line.
The text is hashed as UTF-8, exactly as typed, including spaces and line breaks. To hash a file’s contents or use other algorithms, see the general hash generator.
Example
Input: The quick brown fox jumps over the lazy dog
MD5: 9e107d9d372bb6826bd81d3542a419d6Add a period at the end and the hash changes completely. This “avalanche effect” is what makes hashes useful for spotting any change in data.
Where MD5 is used
MD5 is still everywhere as a fast checksum: verifying that a download or a copied file is intact, cache keys and ETags, deduplicating files, and the Content-MD5 header. It is fine wherever nobody is trying to forge a match.
Security
MD5 is broken for security. Practical collision attacks have existed since 2004: anyone can create two different files with the same MD5. Never use it for passwords, signatures or certificates. For security, use SHA-256. For passwords, use a slow password hash such as bcrypt, scrypt or Argon2.
FAQ
› Is my text sent to a server?
No. The MD5 hash is computed in your browser, so passwords, keys and private text never leave your device.
› Can an MD5 hash be decrypted?
No. MD5 is a one-way hash, not encryption. Sites that claim to decrypt it look the value up in tables of hashes of common words, which only works for short or common inputs.
› Why doesn't my MD5 match another tool's?
Usually the input differs by invisible characters: a trailing newline (echo adds one, use echo -n), Windows CRLF line endings, a leading space, or a different text encoding. This tool hashes the exact UTF-8 bytes of the text box.
› How long is an MD5 hash?
128 bits: 32 hexadecimal characters, or 24 characters in Base64.
› Is MD5 secure?
MD5 is broken for security. Practical collision attacks have existed since 2004: anyone can create two different files with the same MD5. Never use it for passwords, signatures or certificates.