MD5 Hash Generator
Generate the MD5 hash of any text instantly in your browser. UTF-8, hex or Base64 input; hex or Base64 output. Free, private, no upload.
Runs entirely in your browser. Your data is never uploaded.
What is MD5 Hash Generator?
MD5 is the 128-bit hash from RFC 1321 that is still widely used for checksums, cache keys and deduplication. This tool computes the 128-bit MD5 digest of text or raw bytes (hex or Base64) as you type and shows it as 32 hex characters or Base64.
How to use MD5 Hash Generator
- Type or paste your input into Text to hash — the digest updates as you type (an empty box shows the hash of empty input).
- Choose the Input encoding: Text (UTF-8) hashes the characters as UTF-8, Hex bytes or Base64 hash the decoded raw bytes.
- Pick the Output format (hex lowercase, hex uppercase or Base64) and click Copy.
Example
abc
900150983cd24fb0d6963f7d28e17f72
MD5 of the 3 ASCII bytes "abc" (UTF-8, hex lowercase output), the standard test vector.
When to use MD5 Hash Generator
Use the MD5 text tool to hash strings: reproduce a value from documentation or code, build test vectors, compare an API signature input, or check what a program should output. Do not use it to protect anything against attackers — it is cryptographically broken. Do not use it to check a downloaded file: copying file contents into a text box changes line endings and encoding, so use the MD5 file checksum tool. When an attacker could supply the data, use SHA-256 instead.
How MD5 Hash Generator works
MD5 pads the message to a multiple of 512 bits (a 1 bit, zeros, then the 64-bit little-endian length) and processes each block with four rounds of 16 steps on four 32-bit words. Each step mixes in a message word, a sine-derived constant and a rotation. The final state, written little-endian, is the 128-bit (32 hex character) digest. The text is first converted to bytes (UTF-8 by default), so the same characters always give the same hash.
Common Use Cases
- Check the expected MD5 of a string in a unit test or fixture
- Hash hex bytes copied from a debugger, packet capture or protocol spec
- Compare MD5 output between two programming languages that disagree
- Generate deterministic identifiers or cache keys from text
- Reproduce legacy MD5 values stored by an old system
Security Note
MD5 is broken for security. Practical collision attacks exist (e.g. the forged CA certificate of 2008 and the Flame malware), so two different files can share an MD5. It is still fine for detecting accidental corruption, but do not use it for signatures, certificates or passwords — use SHA-256 or SHA-3 instead. Plain hashes are also not suitable for storing passwords: use a slow, salted password hash such as Argon2, scrypt or bcrypt. Everything is computed locally in your browser; nothing you type is sent anywhere.
FAQs
Can an MD5 hash be decrypted?
No. A hash is not encryption, so there is nothing to decrypt. Websites that "reverse" MD5 just look the hash up in huge tables of previously hashed strings, which works for short or common inputs.
Why do two tools give different MD5 values for the same text?
Usually because the bytes differ: a trailing newline, Windows line endings (CRLF) or a different character encoding. This tool hashes exactly the UTF-8 bytes of what is in the box, or the raw bytes when you choose Hex or Base64 input.
Why does the hash change completely when I change one character?
That is the avalanche effect every cryptographic hash is designed for: flipping one input bit changes about half of the 128 output bits, so similar inputs give unrelated digests.
Does a trailing space or newline matter?
Yes. The hash covers every byte, so abc and abc followed by a newline give different MD5 values. Make sure the input contains exactly the bytes you intend to hash.