OpenSolver Website

Our OpenSolver website runs WordPress. Like many WordPress sites, we log usage information (including IP addresses and logons), we use various security modules to monitor for threats, and we also use anti-spam services.  These help keep our site secure, but may result in your activity and/or posts becoming available to third parties.

We also serve ads on our site. Third party vendors, including Google, use cookies to serve ads based on your prior visits to this website. Google’s use of the DoubleClick cookie enables it and its partners to serve ads based on your visit to our site and/or other sites on the Internet. Users may opt out of the use of the DoubleClick cookie for interest-based advertising by visiting Ads Settings or by visiting

Update Checker

As of version 2.7.0, OpenSolver includes a built-in update checker. This is an opt-in feature that will let you know when a new version of OpenSolver is released. If the update checks are enabled (which we recommend), OpenSolver will check periodically in the background for any available updates, with at least one day between checks. These checks run in the background so will not interfere with anything running in Excel, and only run if the user is actively interacting with OpenSolver. (Just opening Excel is not enough to run the check, even if OpenSolver is started up by Excel.)

When OpenSolver is checking with our server for the latest version, the time of day and IP address are automatically logged by WordPress (as mentioned above). The update checker also sends us some additional information about the environment in which OpenSolver is running. This encodes the following data:

  • Operating System: Windows or Mac; Version number (e.g. Windows 8); 32-bit or 64-bit.
  • Excel: Version number (e.g. Excel 2013); 32-bit or 64-bit.
  • OpenSolver: Version number; Linear or Advanced version.

An example of this information is:

Windows/6.2x64 Excel/15.0x32 OpenSolver/2.7.0xLinear

We collect this version information to identify the common environments in which OpenSolver is being used so that we ensure we are testing OpenSolver on these platforms. We hope that collecting this data will help to increase the stability of OpenSolver across all platforms and allow analysis and reporting of aggregate usage patterns. This data will not be used for any other purpose.

If you do not enable the update checker then no information will ever be sent to us by OpenSolver.

NEOS Solvers

OpenSolver allows models to be solved using the cloud-based NEOS solvers. Note that to submit a job, NEOS requires an email to be sent  to NEOS along with the model to be solved.  OpenSolver only sends this email address to NEOS when solving a model and only if you enter the address into the Model > Options menu and then choose to solve the model using a NEOS solver engine.

Submitting a model to NEOS results in it becoming publicly available. Use of NEOS is subject to the NEOS terms and conditions.

OpenSolver for Google Sheets

For Google Sheets OpenSolver’s permission guides and privacy information, please visit

14 thoughts on “Privacy”

  1. I tried unsuccessfully using Open Solver in a spreadsheet that requires the calculation of some auxiliary thermodynamic properties through another Excel add-in. Is there any recommendation to resolve this situation?

    1. For most solvers, OpenSolver builds a model from the spreadsheet to give the solver, and so cannot interact with other addins during solving. However, the NOMAD solver just does a brute-force grid search and recalculates the sheet for each trial solution. This means addins can be used with NOMAD. Let us know if this works for you. Andrew

      1. Thanks for your response.
        I used OpenSolver Advanced with NOMAD and I verified that the combination can be used in spreadsheets that require other addins. Unfortunately, its performance was only effective in problems with few variables as indicated by the solvers guide.
        Is there any way to do the same with COIN-OR? It would be a great news!

        1. We cannot turn the addins into formulae, which is what all the other solvers need. So no, only Nomad will work, sorry. Andrew

  2. Regarding your version for Google Sheets, I am concerned that my personal data could get stolen by OpenSolver because you require the following permissions:
    1. View and manage your spreadsheets in Google Drive.
    2. Allow this application to run when you are not present. (No longer required; Google bug still says it is.)
    3. Connect to an external service.

    1. If OpenSolver sends my info to your servers, then what exactly gets sent? The entire spreadsheet? Only those cells specified in the controls? My own GAS scripts?
    2. Do you retain/log any cell data that is sent?

    1. Thanks for your queries. We have no servers of our own, but instead use optimisation servers that are provided publicly or as a commercial service, or run on your own machine. Each of these solvers is detailed in the “Choose a Solver” dialog window. Two examples are:

      The GNU Linear Programming Kit (GLPK) is a software package intended for solving large-scale linear programming (LP), mixed integer programming (MIP), and other related problems. GLPK is free software and licensed under the GNU General Public License 3. OpenSolver uses glpk.js, a Javascript port of GLPK by Henri Gourvest. This solver runs on your machine rather than an external server, and so is likely to be a faster option.

      The NEOS (Network-Enabled Optimization System) Server is a free Internet-based service for solving optimization problems. Models sent to NEOS often have to wait in a queue before they are solved, depending on the current load on NEOS. For this reason, other solvers are usually faster. Submitting a model to NEOS results in it becoming publicly available. Use of NEOS is subject to the NEOS Terms and Conditions.

      The default solver is provided by Google, and runs as a web service under their terms and conditions.

      We send the mathematical equations that define your model to the server; your spreadsheet is not sent.

      Hope this helps,


  3. What all gets uploaded when you upload a model to NAS? I may have accidentally ran a model in a sheet that had some private data. I did not realize that it was being uploaded at the time I was just testing different models. Are only the fields used for the calculation uploaded or the entire sheet?

    1. The spreadsheet is not uploaded. The equations that make up the objective function and constraints are uploaded along with the cell names. It would be very hard to reverse the intent of a model from this. Andrew

  4. Hello Team,
    Can we use OpenSolver used for commercial purpose also?
    Please update, if there any limitations to use OpenSolver.

    1. Yes all fine to use commercially but you must share source code if you change the VBA source code and redistribute it (which no one does… building models is not changing source code). It is under the GPL license. Andrew

    1. The only limits are solve time and memory which depend on the particular problem being solved. Andrew

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