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MD5 Generator

Compute MD5 digests entirely in your browser with UTF-8 support. MD5 is not suitable for security purposes - use SHA-256 instead.

MD5 still turns up all over older systems: the password field of a legacy application, a checksum on a download page, the 16-digit short form that tools of a decade ago produced. This tool returns the 32-digit lowercase digest, the uppercase form and the 16-digit short form (characters 9 to 24) at once, along with the UTF-8 byte count, so it lines up with whichever historical convention is being compared against.

The boundary has to be stated plainly: MD5 has been open to deliberate collisions since 2004 and must not be used for signatures, certificates or password storage. Checking whether a download was corrupted — a case with no adversary — is still fine. New code should choose SHA-256. And its speed, which sounds like an advantage, is precisely what makes it a poor password hash: brute-force is too cheap, so passwords belong in a slow hash such as bcrypt.

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How to use

  1. Paste the text to hash.
  2. Read the 32-digit lowercase digest, the uppercase form and the 16-digit short form.
  3. Check the byte count if the other side is counting UTF-8 bytes.
  4. Use SHA-256 instead for anything security-related.

How it works

Basic usage

Paste or type content into the box and the digest appears instantly in three synchronized forms: the 32-character lowercase hex in the main result (one-click copy), with uppercase and the 16-character short form below. Change any single character — including spaces and newlines — and the result changes completely.

The 32- and 16-character forms

The 32-character digest is the full 128-bit result; the 16-character short form is characters 9–24 of it, a display habit inherited from old phpcms and Discuz systems. They are two views of the same data — the short form is not a "shorter algorithm" and is neither more nor less secure.

Why you shouldn't use MD5 anymore

Since 2004 it has been possible to construct MD5 collisions deliberately: two different files can share the exact same digest. So MD5 must not be used for digital signatures, certificates or password storage; it survives only in "did my download corrupt?" scenarios where tampering resistance isn't required. For security purposes, use this site's SHA-256 tool instead.

Method: MD5 per RFC 1321, with the input encoded as UTF-8. Output is 32 lowercase hex characters; the uppercase form is the same value in capitals, and the 16-character short form takes characters 9–24 of the 32-character digest (the position used by older systems such as phpcms and Discuz). No salting, no HMAC, and no re-encoding of the input.

Code example

JavaScript Computing MD5 in Node 

const { createHash } = require("crypto");

createHash("md5").update("hello", "utf8").digest("hex");
// "5d41402abc4b2a76b9719d911017c592"

// 16-character short form = characters 9 to 24
const full = createHash("md5").update(s).digest("hex");
full.slice(8, 24);

Shell Computing on the command line 

echo -n "hello" | md5sum    # Linux (-n is required, otherwise a trailing newline is included)
md5 -q file.zip             # macOS
md5sum file.zip             # Linux

FAQ

Can an MD5 digest be reversed into the original text?

No. MD5 is a one-way digest — any input is compressed to 128 bits and information is lost, so no inverse exists. Online "MD5 decryption" is really a lookup table: digests of common strings are precomputed and searched. It only works on weak passwords; a salt or long random string defeats it instantly.

What's the difference between 16- and 32-character MD5?

The 16-character form is just characters 9–24 of the 32-character digest — not another algorithm and not more secure. It merely drops the first and last 8 characters for compatibility with legacy display conventions; new code should never truncate, and comparisons should use the full 32.

Is MD5 encryption or a digest?

A digest (hash), not encryption. Encryption is reversible with the key; a digest is not reversible — you can only compare two values. There is no such thing as an "MD5 key"; using MD5 as encryption is a common misconception. Reversible secret storage calls for real encryption like AES.

Can the MD5 verify that a file hasn't been modified?

It guards against accidental corruption (comparing your download against the official MD5), but not deliberate tampering — an attacker can craft a different file with the same digest. For security verification use the official SHA-256 values or signed checksums.

Is storing backend passwords as MD5 safe?

No. Once an unsalted MD5 password database leaks, rainbow tables recover most weak passwords in minutes, and MD5's speed makes brute force dirt cheap. The right approach is a slow password-specific hash — bcrypt, scrypt or Argon2 — with a unique random salt per user.

What should I watch out for with mixed Chinese and English text?

Watch the encoding. This tool always encodes as UTF-8; the same character under a different encoding produces different bytes and therefore a different digest. When comparing with a server, confirm both sides use UTF-8 — otherwise identical text yields different digests.

MD5 vs. SHA-1 vs. SHA-256 — which should I choose?

For any security purpose, SHA-256 or above. SHA-1 and MD5 both have practical collision attacks and survive only in legacy compatibility. For non-security fingerprints of static assets MD5 is marginally faster, but the gap is tiny — not worth the risk.

Is my input uploaded or saved?

No. Computation happens locally in your browser; the text never crosses a server, never enters access logs, and is never written to localStorage — this tool deliberately has no history section because inputs may contain passwords or keys. Even so, real passwords shouldn't be pasted into any online tool.