MD5 Hash Generator

What this tool does

MD5 Hash Generator computes the 128-bit MD5 digest defined in RFC 1321 for text, raw bytes or files, streaming large files in chunks with a progress bar. It can hash every line of a list separately, compare the result with an expected value and export an md5sum-compatible checksum file.

MD5 turns any input into a fixed 128-bit value, written as 32 hexadecimal characters. The same input always gives the same hash, and changing a single bit changes about half of the output, so MD5 is a quick way to check that a file arrived intact, to detect duplicate files, to build cache keys or to fill a database column that legacy software expects. The empty string, for example, always hashes to d41d8cd98f00b204e9800998ecf8427e.

This generator implements RFC 1321 through a WebAssembly hashing library, so it is fast even for multi-gigabyte files, which are read in 4 MB chunks rather than loaded into memory. Text is hashed as UTF-8 by default, or you can supply hex or Base64 bytes. Batch mode hashes each line separately, file mode handles many files at once and writes a checksum file in the “hash filename” format that md5sum -c reads, and the comparison field tells you instantly whether a result matches a published value. MD4 is included for legacy systems. Nothing is uploaded.

How to use MD5 Hash Generator

1. Choose Text or Files as the input source.
2. Type or paste text, or drop one or more files.
3. Under Options, keep MD5 as the Algorithm and pick the Output format: lowercase hex, uppercase hex, Base64 or Base64url.
4. Switch on “Hash each line separately” to process a list, one hash per line.
5. Paste a published value into “Compare with expected hash” to check for a match.
6. Copy the hash, or click “Download checksum file” for files.

Tips for better results

• Hashes are case-sensitive to the input: “Hello” and “hello” give completely different results, and so do trailing spaces or a final line break.
• Lowercase and uppercase hex are the same hash; the comparison ignores case.
• On Windows, “certutil -hashfile file.iso MD5” gives the same value as this tool, which helps when checking results.
• Gravatar has historically used the MD5 of the lowercased, trimmed email address; it now also accepts SHA-256.

Common use cases

• Checking that a downloaded file matches the MD5 listed on a mirror site.
• Finding duplicate photos or documents by comparing their hashes.
• Generating cache-busting keys or ETags for static assets.
• Producing test vectors for code that still relies on MD5.

Common mistakes to avoid

• Storing passwords as MD5. Modern GPUs test billions of MD5 guesses per second; use bcrypt, scrypt or Argon2.
• Trusting MD5 to detect deliberate tampering. Attackers can create two different files with the same MD5, so use SHA-256 when security matters.
• Copying text with an invisible trailing newline, which changes the hash and makes a correct value look wrong.