MD5
Calculate MD5 hashes or HMAC-MD5 values from text using UTF-8, UTF-16, Hex, Base64, and other input encodings. Read more
What is MD5?
MD5 is a message-digest algorithm that converts input of any length into a 128-bit hash, normally displayed as 32 hexadecimal characters. The same input bytes always produce the same MD5 value, so MD5 is still useful for reproducing legacy hashes and detecting accidental changes when a trusted checksum is already available.
MD5 was originally specified in RFC 1321. It is no longer considered collision-resistant and should not be used for digital signatures, certificates, password storage, or other security-sensitive designs. RFC 6151 recommends against MD5 wherever collision resistance is required.
How to calculate an MD5 hash
Enter the source value, select its input encoding, and choose the output format. For normal text, use UTF-8. Select Hex or Base64 as the input encoding only when the entered value already represents encoded bytes rather than literal text.
For example, the UTF-8 text abc produces:
900150983CD24FB0D6963F7D28E17F72
Changing capitalization, whitespace, line endings, or input encoding changes the bytes and therefore changes the MD5 result.
MD5 and HMAC-MD5
Enable HMAC when you need a keyed message authentication value rather than a plain hash. HMAC-MD5 combines the message with a secret key, so its result is different from the MD5 hash of the same text. Select the correct key encoding before entering the key.
HMAC-MD5 may still be required for compatibility with an existing protocol, but new systems should normally use a modern alternative such as HMAC-SHA-256. Open the SHA-256 tool for an unkeyed SHA-256 hash.
MD5 FAQ
Can MD5 securely hash passwords?
No. MD5 is fast and collision-broken, and it is not a password hashing function. Password storage should use a dedicated, salted password hashing scheme selected for the target system.
Why does another MD5 tool return a different value?
Check the exact input bytes, character encoding, capitalization, whitespace, and line endings. Also confirm that neither tool has HMAC enabled and that both display the result using the same output encoding.
How do I calculate MD5 for a file?
Use the MD5 File Checksum tool, which processes a local file or URL content instead of interpreting the input as text.