MD5 Hash Generator
Type or paste text to see its MD5 hash instantly, hash a whole list line by line, or drop files of any size to get their MD5 checksums. Everything is computed in your browser, so nothing is uploaded.
How to use the MD5 Hash Generator
- Choose Text or Files. Type or paste text, or drop one or more files onto the box.
- Read the MD5 hash: text is hashed as you type, files start hashing as soon as you add them.
- Tick Hash each line to get a separate MD5 for every line of a list, for example emails or IDs.
- Paste an expected checksum in the Verify box to see at once whether it matches.
- Copy a hash, switch to uppercase, or press Download to save the results as an .md5 file.
MD5 test vectors
These values come from the MD5 specification (RFC 1321) and let you check that any MD5 tool or library works correctly. Type the input above (without quotes) and compare.
| Input | MD5 hash |
|---|---|
| "" (empty) | d41d8cd98f00b204e9800998ecf8427e |
| "a" | 0cc175b9c0f1b6a831c399e269772661 |
| "abc" | 900150983cd24fb0d6963f7d28e17f72 |
| "message digest" | f96b697d7cb7938d525a2f31aaf161d0 |
| "abcdefghijklmnopqrstuvwxyz" | c3fcd3d76192e4007dfb496cca67e13b |
| "The quick brown fox jumps over the lazy dog" | 9e107d9d372bb6826bd81d3542a419d6 |
Adding a full stop to the last sentence ("…lazy dog.") gives e4d909c290d0fb1ca068ffaddf22cbd0: one extra byte changes the whole hash, which is called the avalanche effect.
What MD5 is still good for
- Download checks: many mirrors and older projects publish MD5 checksums to detect a corrupted or incomplete download.
- Finding duplicates: files with different MD5 hashes are certainly different, so MD5 is a fast way to spot duplicate photos or backups.
- Cache keys and ETags: a short, stable fingerprint of content for caching, deduplication and change detection.
- Gravatar and legacy APIs: some services identify an item by the MD5 of a normalised string (for example a trimmed, lowercase email address). Bulk mode with Trim spaces is handy here.
Do not use MD5 to store passwords, sign documents or prove that a file was not tampered with by an attacker. Collisions can be created in seconds on a laptop. Use SHA-256 for integrity and bcrypt or Argon2 for passwords.
MD5 on the command line
| System | File | Text (no trailing newline) |
|---|---|---|
| Linux | md5sum file.zip | printf '%s' 'abc' | md5sum |
| macOS | md5 file.zip | md5 -s 'abc' |
| Windows PowerShell | Get-FileHash file.zip -Algorithm MD5 | (hash a file instead) |
| Windows CMD | certutil -hashfile file.zip MD5 | (hash a file instead) |
Beware of echo 'abc' | md5sum: echo adds a newline, so it prints the MD5 of "abc\n" (0bee89b07a248e27c83fc3d5951213c1), not of "abc". The .md5 file this tool downloads uses the same format as md5sum, so you can check files later with md5sum -c checksums.md5.
How MD5 works
MD5 was designed by Ronald Rivest in 1991. It pads the message so its length is 64 bits short of a multiple of 512 bits, appends the original length as a 64-bit number, and then processes the data in 512-bit blocks. Each block passes through four rounds of 16 steps that mix it into a 128-bit state of four 32-bit words using additions, bit rotations and the non-linear functions F, G, H and I, with constants taken from the sine function. The final state, written in little-endian byte order, is the hash. Practical collisions were published by Xiaoyun Wang and colleagues in 2004, and in 2012 the Flame malware used an MD5 collision to forge a Microsoft code-signing certificate.
Frequently asked questions
What is an MD5 hash?
MD5 (Message-Digest Algorithm 5, RFC 1321) turns any input into a 128-bit value, written as 32 hexadecimal characters. The same input always gives the same hash and a one-character change gives a completely different one, which makes MD5 handy for checksums and for spotting duplicate files.
Is MD5 secure?
No, not for security. Researchers can create two different files with the same MD5 hash (a collision), so MD5 must not be used for digital signatures, certificates or password storage. It is still fine for detecting accidental corruption, cache keys and matching checksums that a website publishes.
Can an MD5 hash be decrypted?
No. A hash is not encryption and cannot be reversed. Websites that claim to 'decrypt' MD5 only look the hash up in huge tables of hashes of common words and passwords, which is why short or common inputs can be found.
Why is my MD5 different from another tool?
MD5 works on bytes, so encoding and invisible characters matter. This tool hashes the text as UTF-8, exactly as it is in the box, including spaces and line breaks. A trailing newline (as added by echo on the command line), Windows CRLF line endings or a different encoding change the hash.
How do I check a file's MD5 on my computer?
On Linux run md5sum file, on macOS run md5 file, and on Windows run certutil -hashfile file MD5 in Command Prompt or Get-FileHash file -Algorithm MD5 in PowerShell. The result should match the hash shown here.
Is there a file size limit?
No fixed limit. Files are read in small chunks, so even multi-gigabyte files can be hashed without loading them into memory at once. Very large files simply take longer.