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Before you download, it is recommended that you register below as CHEAQS user, because then you will be informed about updates and bugs. You can expect two to four emails per year. Of course your email will not be used for anything else.

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The current stable version is CHEAQS Next. In addition to that, a (not yet complete) new version is available, especially designed for 64-bits operating systems. More information below the table. You can download CHEAQS Next by clicking in the table below. Stay tuned (e.g. on Facebook or by registering below).

CHEAQS Next (2015 till now) (click here to download): version 2020.2
CHEAQS Next (64-bits only; almost complete version) (click here to download): version
Release date
July 2020
January 2022
CRC 32
CRC 64
Size of setup
1.3 Mb
1.3 Mb
Operating system
Windows XP and higher (incl. Windows 10)
Windows 7 and higher but only if 64-bits
Database document
Click here to download
Click here to download version (also valid for
Click here to download Click here to download version (also valid for

See the table below for a comparison of the versions.

Features 32-bits 64 bits
Titrations Yes Not yet
Database manipulation routines Yes Not yet (viewing included since
Mean Spherical Approximation model No Yes
Temperature correction No Yes
Built-in charge balance correction No Yes
Unicode No Yes
Built-in support for different languages No Yes
Estmated stability 99.9% 99.9%
Fully functional print preview No Yes
Revised start menu look and feel
No Yes
Improved calculation speed No Yes
View output sets side by side No Yes
Downloading and viewing the manual and database document from within the program No Yes

I recommend not to download CHEAQS from other sites. Only downloading CHEAQS from here guarantees a secure and up-to-date download. Also, I recommend not to use any other uninstallers than the one included with CHEAQS Next. Their 'solution' is usually worse than the supposed problem.

Regarding the new 64-bits version: already some time ago I decided I wanted to make a new version of CHEAQS, especially designed for 64-bits systems. The new version includes the MSA-model (Mean Spherical Approximation model). This model is able to predict ion activities at high salt concentrations. Unlike many other available models (which are at best semi-empirical), the MSA-model has a solid theoretical basis. Of course there is always a ‘but’. The ‘but’ here is that at this moment the required derivations are available only for a limited number of ions, but I expect that this number will increase soon. I prefer to invest in a method with a solid theoretical basis than in a method that will never become more than semi-empirical. I am grateful to Prof. Jean-Pierre Simonin (CNRS, Paris, France) who developed this model and helped me with the implementation in CHEAQS. Together we prepared a paper that was recently accepted.

This new version is now almost complete as you can see from the table above.