MD5 Hash Generator

MD5 turns any text into a 32-character fingerprint. It's no longer safe for passwords or signatures, because researchers can make different inputs with the same hash, but it's still everywhere for checksums, cache keys and matching old systems. Type text to see its MD5, or paste a hash you were given to compare.

How to use it

1. Type or paste your text.
2. Read the MD5 hash.
3. Optionally paste a hash to compare against.
4. Copy the result.

When it helps

• Checking a file or message wasn't changed by accident.
• Making a cache key or identifier.
• Matching a hash from older software.
• Learning how hashes behave.

Good to know

• The same text always gives the same hash, and a tiny change gives a completely different one.
• Spaces and line breaks count, so a trailing newline changes the result.
• For anything security related, use SHA-256 or better.

What a hash function does

A hash function turns any input into a fixed-length fingerprint. MD5 produces 128 bits, shown as 32 hex digits. The same input always gives the same output, a tiny change in the input changes the output completely, and you can't reasonably work backwards from the hash to the input.

For example, the MD5 of the word abc is 900150983cd24fb0d6963f7d28e17f72, and of an empty string d41d8cd98f00b204e9800998ecf8427e.

Worked example: verifying a download

A site publishes a file with an MD5 of a known value. After downloading, you hash the file and compare. If they match, the file arrived intact. For text, paste it here and compare against the expected hash in the second box.

For files, use the File Hash Checker. For anything security-sensitive, a publisher should provide SHA-256 instead.

Why MD5 is retired for security

In 2004 researchers showed how to create two different messages with the same MD5, and later work made it practical to forge certificates. That means MD5 can't prove a file wasn't deliberately altered, only that it wasn't accidentally damaged.

Never use it to store passwords. Use a purpose-built password hash like Argon2, bcrypt or scrypt.

Where MD5 is still fine

Non-security uses include cache keys, deduplication of files, ETag values, and quick checks of whether two files are likely the same. It's fast and universally supported.

If an attacker might benefit from creating a collision, choose a stronger hash.

Hashing text versus files

Hashing the text of a file isn't the same as hashing the file, because the file may contain line endings, a byte order mark or other bytes you don't see. For files, use the File Hash Checker to hash the real bytes.

Even a trailing space or newline changes the result.

Questions