About JMd5Sum

I’m used to living in a Unix world which is one where when I want to know the MD5 sum for a downloaded file I can just type “md5sum filename” and it tells me the digest bytes. That’s useful for making sure your download wasn’t corrupted in some way. Because of my laptop I need to live in a windows world sometimes and not having easy access to an md5sum command line utility prompted me to make a GUI one that would work in Linux, OSX and Windows.

By the way, it also does SHA1 sums, as that’s becoming the favorite after some recently discovered vulnerabilities with MD5.

Previously I had a blurb right here about how the program was slightly slow compared to other implementations. Still true, but now it’s much, much faster. Probably half as fast as a pure C implementation, so it’ll do a 100 mb file in a few seconds, not a minute or more like before (on relatively modern machines).


This software is distributed under the terms of Apache License version 2.0. This code includes software that is part of the Jakarta Commons project (namely the hex encoder).


You’ll need Java 2 version 1.5 available to run this software. With that installed, download the newest jar file below and save it someplace useful (like My Documents or your home directory). To run it just double-click it in windows. On other platforms or from the command line just run java -jar jmd5sum.jar.

With this piece of software I’m changing my distribution steps. Instead of distributing a single jar file I’m distributing a zip or tgz file with all the software and libraries inside. That way I’m not doing anything questionable by including unjarred libraries inside of my jar. The software should still work with the instructions above.



Launch JMd5Sum via webstart!

One Comment

  1. […] In other news, I’m about done with a little GUI program to generate MD5 and SHA1 sums.  It’s Java (of course) and runs just about everywhere.  If you download big files you know how useful this little utility could be to tell whether your download is corrupt or not.  It should be available for download in the next two days so go get it. […]