OpenFOAM

OpenFOAM is a desktop computational fluid dynamics toolbox for simulating flow, heat transfer and related physical processes. It is best suited to science and engineering users who want to shape their own simulation workflow. Its broad toolset is free under the GPL, but help from OpenCFD is a separate, limited-hours service.

Overview

OpenFOAM covers the main stages of CFD work: preparing meshes, running solvers across multiple flow and physics types, and post-processing results. That breadth makes it a strong fit for teams whose work spans different simulation problems; it is less suited to readers looking for a narrowly packaged application with support included.

The software is distributed under the GNU General Public Licence (GPL). The current release is v2606, released on 26 June 2026. It introduces GPU offloading as a compile-time option, but GPU development remains on a separate track, so users should not treat it as a settled, general-purpose GPU workflow.

Key features

Mesh preparation and simulation

Built-in mesh tools include blockMesh and snappyHexMesh, and OpenFOAM can convert meshes from several external formats. Together with its range of solvers, these tools let users handle mesh preparation and simulation within one toolbox. That flexibility is valuable for varied CFD work, but it puts the emphasis on users choosing and configuring the right tools for each case.

Visualisation and output

OpenFOAM integrates with ParaView through the paraFoam launcher and reader modules, and can also convert results to VTK or write VTK output during simulations. This gives users several routes into 3D visualisation and data export without making ParaView the only part of the workflow.

Security and privacy

User-supplied system calls are disabled unless allowSystemOperations is enabled. OpenFOAM’s documentation warns that enabling system calls carries security risk, so teams should weigh that setting carefully. OpenCFD says personal data is kept on its or a supplier’s server with precautions against fraudulent access and is not retained longer than necessary.

Pricing

OpenFOAM — free. The GPL software is free and open source, with no free-trial period. This is the natural choice for individuals and organisations able to manage their own installation and CFD work; the free plan does not include support or code customisation.

OpenCFD sells a one-year support package covering installation, bug fixes, updates, CFD assistance and code customisation. The package has a maximum number of service hours per year, and OpenCFD does not respond to support queries without a prior package. Pricing is custom pricing. Training is also offered separately, including Foundation, Advanced, application-focused and virtual courses; pricing is provided through its schedule or enquiry process.

Platforms

OpenFOAM is desktop software for Linux, macOS and Windows, and is also available for self-hosted use. Its ParaView integration and data-export options suit users who need to inspect and share simulation results as part of a broader workflow.

Who it's for

OpenFOAM is aimed at science and engineering companies, consultancies and universities. Its combination of mesh tools, solvers and post-processing makes it particularly suitable for teams with varied CFD needs and the capacity to work with a configurable toolbox. If your priority is assistance, code customisation or instruction, budget for OpenCFD’s separate services and their hour or course terms.

Pros and cons

• Pros: Free GPL software provides mesh generation, solvers for multiple flow and physics types, and post-processing in one toolbox.
• Pros: ParaView integration, VTK conversion and VTK output support flexible visualisation and export workflows.
• Cons: Support and code customisation cost extra, require a prior package, and are bounded by annual service hours.
• Cons: GPU offloading is a compile-time option on a separate development track, which limits how much users should rely on it as a standard GPU path.

Alternatives

OpenSim is another free, open-source option, with Linux, macOS and Windows support; downloading it requires a SimTK account.

SimFlow may suit readers who want to consider a freemium alternative with a free trial, across Linux, macOS, Windows and web.

Xcos is a free option for Linux, macOS and Windows, distributed with Scilab.

ngspice is free and available for Linux, Windows and self-hosted use, but it is a circuit simulator with command-line or file-based input and no schematic entry.

Open Source Physics is a free alternative spanning Android, iOS, Linux, macOS, web and Windows.

FeenoX is a free GPLv3+ option for Linux, self-hosted and web use, but it has no graphical interface and its generic binaries omit MUMPS and MPI.

COMSOL Multiphysics is a paid alternative with a free trial and a perpetual commercial or academic licence priced by quotation.

GNU FisicaLab is free software for Linux and Windows.

Verdict

Choose OpenFOAM if you need a free, GPL CFD toolbox that brings mesh preparation, simulation and post-processing together, and you can manage the workflow yourself. Look elsewhere if your work depends on GPU capability as a settled standard path, or if you need included support: OpenCFD’s assistance and customisation require a paid package with an annual service-hours ceiling.