About MD5 Hash Generator
This MD5 hash generator computes the MD5 digest of your text or file. MD5 produces a 128-bit value, written as 32 hexadecimal characters. It is free, needs no sign-up and runs in your browser, so nothing you enter is uploaded.
MD5 is broken as a security hash. Researchers found collisions in 2004, and today two different files with the same MD5 can be built in seconds on an ordinary computer. Do not use it for signatures, certificates or passwords. Use SHA-256 or SHA-3 instead.
It is still common as a plain checksum, because many download pages, package mirrors and backup tools publish an MD5 next to each file. For catching a corrupted or truncated download it works fine, as long as you accept that it cannot protect you against someone who deliberately swaps the file. Paste the published value into the compare box to check it.
MD5 is also a legacy key in older systems, such as cache keys, deduplication and some Gravatar-style lookups. Hashing the text "hello" gives 5d41402abc4b2a76b9719d911017c592. Hashing "hello" followed by a newline gives b1946ac92492d2347c6235b4d2611184, which is the value you get from the Linux command echo hello | md5sum.
How to use MD5 Hash Generator
- Choose an algorithm from the row of buttons: MD5, SHA-1, SHA-224, SHA-256, SHA-384, SHA-512, SHA3-256, SHA3-512 or CRC32. SHA-256 is a good default.
- Choose Text and type or paste your input, or choose File and pick a file from your device. The hash updates as you type.
- Read the digest in the result box. Tick Uppercase for capital hex letters, or Base64 output to show the digest in Base64 instead of hex.
- For a keyed hash, tick HMAC with secret key and enter the key. The result is then labelled HMAC-SHA-256 (or whichever algorithm you chose).
- To verify a download or a value from documentation, paste the expected hash into Compare with a known hash. The tool says Match or No match.
- Use Copy to put the digest on your clipboard.
Features
- Nine algorithms: MD5, SHA-1, SHA-224, SHA-256, SHA-384, SHA-512, SHA3-256, SHA3-512 and CRC32.
- Hashes text as UTF-8, so accented letters, other scripts and emoji hash the same way as on a server or in a command-line tool.
- Hashes a file you choose from your device. The file is read in your browser and never uploaded.
- HMAC with a secret key for every algorithm except CRC32, following RFC 2104.
- Hex output in lowercase or uppercase, or Base64 output.
- Compare with a known hash. Case, spaces and a leading 0x are ignored, and the expected value can be hex or Base64.
- SHA-1, SHA-256, SHA-384 and SHA-512 use the Web Crypto API in your browser, which is fast and well tested.
- A warning appears when you pick MD5, SHA-1 or CRC32, because they are not safe for security purposes.
- One-click copy of the result.
Worked examples
MD5 of "abc" gives 900150983cd24fb0d6963f7d28e17f72
The RFC 1321 test vector.
MD5 of an empty input gives d41d8cd98f00b204e9800998ecf8427e
The MD5 of every empty file.
MD5 of "The quick brown fox jumps over the lazy dog" gives 9e107d9d372bb6826bd81d3542a419d6
Add a full stop at the end and it becomes e4d909c290d0fb1ca068ffaddf22cbd0.
Privacy: how it works
- The text, the file and the HMAC key stay in your browser tab. Nothing is sent to Ulkaa or to any other server, which you can confirm in the Network tab of your browser developer tools.
- Because the work happens on your own device, large files are limited by your browser memory rather than by an upload limit.
Tips
- To verify a download, choose File, pick the downloaded file, and paste the publisher hash into the compare box. A match means the bytes are identical to what the publisher hashed.
- Hash the same text twice with a trailing space added once. Seeing two unrelated digests is the quickest way to understand the avalanche effect.
- A hash you found on the same page as the download only protects against corruption. It cannot protect you if the page itself was altered.
- HMAC takes the key as plain text. If your key is hex or Base64, decode it first, or the result will not match another system.
Frequently asked questions
Is it really free?
Yes. There is no price, no trial and no credit card. Ulkaa Tool does the work with your own device, so there is no server bill to pass on to you.
Do I need an account?
No. There is no sign-up and no login. Open the page and use it. An Ulkaa account is not needed for anything on this tool.
Does it run in my browser?
Yes. Your text and files are processed by code running in your browser tab, on your own device.
Is my data uploaded?
No. Your text and files are never sent to Ulkaa or to anyone else. You can check this yourself by watching the Network tab in your browser developer tools while you use the tool.
Is MD5 still safe to use?
Only for non-security checksums. Collisions are easy to create, so an attacker can make a harmful file with the same MD5 as a harmless one. For anything security related use SHA-256, SHA-512 or SHA-3.
Can I decrypt an MD5 hash?
No. MD5 is one-way. Websites that claim to decrypt it only look the hash up in a table of known inputs, so short and common strings such as "password" are found and long random ones are not.
Why is my MD5 different from md5sum on Linux?
Most often echo added a newline to the text. Use printf with the text, or paste the exact bytes here. This tool hashes the characters you enter as UTF-8, with nothing added.
More Hash Generator pages
- Hash GeneratorHash text or a file with MD5, SHA-1, SHA-2, SHA-3 or CRC32, add an HMAC key, and check the result against a known hash.
- SHA-1 Hash GeneratorGet the 160-bit SHA-1 hash of text or a file as 40 hexadecimal characters.
- SHA-224 Hash GeneratorGet the 224-bit SHA-224 hash of text or a file as 56 hexadecimal characters.
- SHA-256 Hash GeneratorGet the 256-bit SHA-256 hash of text or a file as 64 hexadecimal characters.
- SHA-384 Hash GeneratorGet the 384-bit SHA-384 hash of text or a file as 96 hexadecimal characters.
- SHA-512 Hash GeneratorGet the 512-bit SHA-512 hash of text or a file as 128 hexadecimal characters.
- SHA3-256 Hash GeneratorGet the 256-bit SHA3-256 hash of text or a file as 64 hexadecimal characters.
- SHA3-512 Hash GeneratorGet the 512-bit SHA3-512 hash of text or a file as 128 hexadecimal characters.
- CRC32 Checksum CalculatorCalculate the 32-bit CRC32 checksum of text or a file as 8 hexadecimal characters.
- HMAC-SHA256 GeneratorSign a message with a secret key using HMAC-SHA256 and read the result as hex or Base64.
- File Checksum CalculatorHash a file on your device and compare it with the checksum the publisher gave you.