MD5 Hash
Generate MD5 hashes in 16 or 32 characters, upper or lower case, with batch input
About this tool
MD5 (Message Digest Algorithm 5) is a widely used hash function that maps data of any length to a fixed 128-bit value, shown as 32 hexadecimal characters. It appears in password storage, file integrity checks and digital signatures.
- 32-character lower case: the standard form, for example
d41d8cd98f00b204e9800998ecf8427e - 32-character upper case: some systems require capitals such as
D41D8CD98F00B204E9800998ECF8427E - 16 characters: the middle 16 characters of the 32-character hash
- Salt: append or prepend a secret value so rainbow tables no longer help
- Batch mode: hash many lines of text at once
When to use it
- Storing password hashes, preferably with a salt
- Verifying a download was not altered
- Checking API request signatures
- Comparing records for duplicates
Security note: MD5 is one way, so the original cannot be recovered from the hash. Collisions are proven, though, so avoid MD5 for high-security password storage and prefer SHA-256 or stronger.
MD5 notes
- 16 vs 32 characters: the 32-character value is the full hash; the 16-character form takes characters 9 to 24
- Case: the output is hexadecimal, so a-f and A-F are the same value in a different display format
- Salting: a random value appended or prepended makes identical passwords hash differently and defeats rainbow tables
- One way: there is no reverse operation from hash to original text