Updated 4 September 2022. This is the main download page of Visual MINTEQ. The current version is 3.1. From May 2022 a beta version of 4.0 is available as well – although this version is completed, it has not yet been extensively checked and you should be aware that it may still contain some unknown bugs in the code. Various databases for use with version 3.1 can also be downloaded. Currently, I use the Google and OneDrive platforms to distribute the software. Disregard the message saying that “We’re sorry, this file type is not currently supported” and click on the Download button. If the links don’t work please send me an e-mail!

Visual MINTEQ version 3.1

Visual MINTEQ 3.1 can be downloaded from the following links:



Last modified 26 November 2020.

This is the official and final 3.1 version. This version relies on .NET Framework 4.5 and is adapted for Windows 8 and 10 users. Most Windows 7 users should also be able to use it without any problems – however, in case it does not launch, please download .NET Framework 4.5 from Microsoft and then try again. The version of 26 November corrects an error in the numerical optimization routine of the previous version, which caused poor convergence for some “pH from mass balance” problems.

Installation instructions: 1. Uninstall any previous version of Visual MINTEQ, 2. Save the file (link above) to your computer. 3. Extract the setup file from the zip file. 4. Click “setup.exe” to initiate installation. When using the software the first time, you will need to decide where to put your user-editable files. The default location is in the My Documents folder.

For information on the release of new versions, discussion etc., join the Visual MINTEQ group on Facebook.

Visual MINTEQ version 4.0, beta (4.02)

At first sight, the new Visual MINTEQ 4.0 looks similar to version 3.1, but “under the hood” a lot of things have changed. The calculation part of the code has been rewritten in C#, which will facilitate future cross-platform development. Moreover, the program runs much faster. This version contains new updated surface complexation models for ferrihydrite. Although the current version may still contain some minor issues, I’d say that it now works fine. However, I would very much welcome feedback on this version. Note the following, however:

  • Adsorption “isotherms”, i.e. empirical equations such as Freundlich, Temkin and Langmuir, have not yet been implemented, please use version 3.1 if this is of interest to you. The plan is that they will be added back into the program during 2023.
  • The Gaussian DOM model is no longer present in Visual MINTEQ. If you are interested in using this model, please use Visual MINTEQ 3.1.

Currently, the installation zip file can only be downloaded from OneDrive. For the vast majority of users, it is the 64-bit version that should be downloaded. If it doesn’t work for you, you can try the 32-bit version instead (if you think you have a 32-bit Windows computer). You need to have Windows 10 or 11 to use Visual MINTEQ 4.0. Please note that the C# code needs the .NET 6.0 runtime. If you do not have it on your computer, it will be installed by the setup program before it goes on to install Visual MINTEQ.

Last update: 4 September 2022. This version fixes issues related to the use of surface complexation models in cases when the surface is tied to a precipitated solid.

64-bit version:

32-bit version:

Visual MINTEQ version 3.0

This version from October 2012 is still available on the site although I strongly recommend later versions as they include a number of bug fixes not addressed in version 3.0. The OneDrive link is:

Last modified 18 October 2012.

Older Visual MINTEQ versions

If you have a very old Windows operating system (i.e. Win98 or earlier), or if your .NET Framework doesn’t work, you can download version 2.40b from January 2006 below, which was the last version that did not use .NET Framework at all. Note however that this version lacks a large number of new functionalities present in later versions. OneDrive link:

Last modified 23 January 2006

Alternative thermodynamic databases

In general, I recommend the use of the databases that accompany the standard version of the program, as included in the above setup package. However, there are other alternatives. Below are the databases of MINTEQA2 (version 4.0) and Lindsay’s databases, adapted for the Visual MINTEQ format in 2003. Unzip the files to your folder of user-editable files (this folder is defined on “Parameters” – “Various default settings”). Read the “readme” file before using any of these databases. The OneDrive links: