Overview

TopOpt is the short name for topology optimization, and the DTU group develops and applies density-based methods. The joint effort spans DTU Mechanical Engineering and DTU Compute in Kongens Lyngby, Denmark.

This is a collection rather than one unified app: it ranges from interactive 2D and 3D tools to compact code and a PETSc-based framework for large-scale work. That breadth is useful to people moving from introductory examples to specialized structural or photonics problems, but readers should choose by task rather than expect one package to cover every workflow.

Key features

Interactive tools and teaching code

Interactive 2D and 3D apps are offered for handheld devices and the web. The 99-line MATLAB code targets engineering education and newcomers, while additional MATLAB code and a 200-line Python implementation address minimum-compliance problems. The short implementations make the core problem more approachable; they are not substitutes for the parallel framework when scale is the priority.

Specialist methods and framework

TopBuck250 extends top99neo to 2D buckling, including buckling-load-factor maximization and minimum-volume design with compliance and buckling constraints. For photonics, the offering combines a 200-line MATLAB code for 2D cylindrical metalens design with five COMSOL Multiphysics models.

The PETSc-based framework is the more substantial option for very large structured-grid problems. It includes mesh and optimization parameters, a 3D linear-elasticity solver, standard and PDE-based filters, parallel MMA, and IO and Python script converters. Its reliance on PETSc and recommendation of ParaView 4.0 or newer for visualization make it better suited to technical workflows than casual exploration. TopOpt for Grasshopper is also part of the software collection.

Pricing

The plan “TopOpt apps and software” is 0.00 USD per free. Free MATLAB code covers minimum-compliance and buckling optimization, and free MATLAB and COMSOL code is offered for photonics. No seat counts, quotas, or trial terms are given for that plan. The interactive apps have no stated price, so do not assume their pricing from the free code.

For readers choosing among the free resources, the compact educational code is the natural starting point; the PETSc framework is the better fit when parallel, very-large-scale optimization is required. The difference is capability and scope, not a published paid tier.

Platforms

The 2D app is listed for iOS, Android, Linux, Mac OS X, and Windows; the 3D app is listed for iOS, Windows, and Mac OS X. The apps are also described as available on the web. Windows downloads for both apps require VC++R2012 and VC++R2013, a practical setup requirement for Windows users. Platform tags also include Linux, macOS, Android, and iOS, but code and framework requirements depend on the particular offering.

Who it's for

Students and newcomers should start with the 99-line MATLAB example, while researchers can select code for minimum compliance, buckling, or photonics. Teams working on very large structured grids have a stronger reason to consider the PETSc framework and its parallel components. Readers who need a polished, single-purpose commercial product or a published support commitment should look elsewhere: TopOpt's maker pages provide no security or compliance statements and no support plan.

Pros and cons

Pros: The collection spans introductory code, interactive apps, specialist examples, and a parallel framework, giving technically minded users options at different scales.
Pros: The photonics and buckling resources address concrete optimization problems rather than only general topology optimization.
Cons: Windows app downloads require two VC++ runtimes, adding setup work for users who do not already have them.
Cons: The range of separate resources means readers must match the tool to their problem; the collection is not presented as one integrated application.
Cons: No support plan or security and compliance statements are provided, which may rule it out for organizations with formal operational requirements.

Alternatives

For an overview of related category options, see Generative Design Software.

NETVIBES may suit readers seeking paid enterprise data-science software, with a free plan and free trial, rather than topology-optimization code.
Avocado is a free, early-development option for readers focused on game compatibility; it requires a PlayStation BIOS and compatibility varies.
Dakota is a free alternative for users seeking open-source software under the GNU LGPL.
Plato may be preferable when its limited open-source set of objectives and constraints is sufficient, or for U.S. government agencies and contractors considering its licensed version.
Ansys optiSLang is a paid option with a free trial; its Pro plan lists unlimited parameters, constraints, and objectives and LS-OPT enabled.
modeFRONTIER is a paid alternative for readers seeking commercial licensing options through ESTECO.
FEniTop is another free option for Linux or Windows users.
CAESES may suit readers seeking paid geometry modeling and design-study tools, with a free trial.

Verdict

Choose TopOpt if you need accessible topology-optimization teaching code, a focused research implementation, or a PETSc-based route to very large structured-grid problems. Its strongest case is the range from compact examples to parallel methods; look elsewhere if you need a single supported commercial product or formal security and compliance assurances.

	nTop	TopOpt
Free plan	Yes	Yes
Free trial	No	No
Paid from	Free	Free
Open source	No	No
Platforms	Linux, Windows	Android, iOS, Linux, macOS, Web, Windows
Free plan	—	Yes
Simulation integration	—	Yes
Native CAD integration	—	Yes
Optimization methods	—	topology

nTop vs TopOpt

nTop

TopOpt