MD5 Hash Generator

Type or paste into the box and the MD5 hash updates with every keystroke. The text is encoded as UTF-8 before hashing, and the result is always 32 lowercase hexadecimal characters, however long the input. hello gives 5d41402abc4b2a76b9719d911017c592.

With the box empty you'll still see a hash, d41d8cd98f00b204e9800998ecf8427e. That's the MD5 of zero bytes, not an error. If you see it in your own system's data, something hashed an empty value, often a missing form field or a variable that was never set.

The tool hashes text only. To get the MD5 of a downloaded file, use the command line: certutil -hashfile file.zip MD5 on Windows, md5sum file.zip on Linux or md5 file.zip on macOS.

One changed byte gives a completely different hash, and the usual culprit is a character you can't see:

• Trailing line break: echo hello | md5sum hashes the line break that echo adds, which is the second row. Use printf hello or echo -n hello to match the first.
• Line endings: the box stores line breaks as a single line feed. Text from a Windows file with CR LF endings hashes differently there than here.
• Accented letters: café can be stored as one character for é or as e plus a combining accent. They look identical but give 07117fe4… and 10a85865….
• Letter case of the hash: some systems print MD5 in capitals. Compare case-insensitively, or lowercase theirs first.

MD5 is no longer chosen for new security designs, but plenty of existing systems still use it as a fingerprint, and that's where this page helps:

• Looking up a row in a legacy table where a column stores the MD5 of an email address or a URL.
• Checking that a cache key or deduplication key your code builds matches what you expect.
• Reproducing a checksum that an older API or file format requires for a text field.

For new work that needs a fingerprint, SHA-256 is the safer default.