MD5 Hash Generator
128-bit MD5 digest of the input bytes. Prefer SHA-256 for new integrity work; keep MD5 to match a published legacy checksum.
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How to generate an MD5 hash
- Paste text, hex, or Base64 into Input.
- Set Input encoding to match those bytes (UTF-8 for normal text).
- Choose hex or Base64 output. Turn on HMAC and enter a key if you need a keyed digest.
- Copy the result. For new integrity checks, use SHA-256 instead.
MD5
Cryptographic hash function (legacy checksum)
| Digest size | 128 bits (32 hex characters) |
|---|---|
| Block size | 512 bits |
| Designed | Ronald Rivest, 1991 |
| Collision resistance | Broken in practice. Do not use for security |
| HMAC | Optional HMAC-MD5 with a separate key encoding |
What MD5 is
MD5 is a one-way hash: the same bytes always produce the same 128-bit digest, and you cannot recover the input from the digest alone. It was widely used for file checksums. Practical collision attacks exist, so it is not a security primitive.
Need a stronger checksum? Use SHA-256. Matching an older Git or vendor digest? Try SHA-1. All three are in hash tools.
How this page hashes
The input encoding turns what you paste into bytes, then MD5 (or HMAC-MD5) runs on those bytes. Empty input hashes the empty byte string, which is a defined digest, not an error. East-Asian encodings that the browser cannot encode will ask you to use UTF-8 or paste hex / Base64 instead.
When to use MD5, and when not to
Use MD5 only to match an existing checksum, such as an old ISO, a CMS field, or a vendor note. Do not use it for passwords, signatures, or TLS. For those jobs use a modern hash such as SHA-256, or a dedicated password hash such as Argon2 or bcrypt in your own stack.