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CAD · head to head

SolveSpace vs Three.js

S

SolveSpace

CAD

Open source parametric CAD with a constraint solver in a few megabytes

From
Free
Rated
-
Full reviewWebsite
Three.js logo

Three.js

AR VR

JavaScript 3D library for WebGL and WebXR

From
Free
Rated
-
Full reviewWebsite

The short version

  • Each has a real cost: SolveSpace the in-house geometry kernel fails on complex boolean operations and fillets, and the failure is sometimes silent bad geometry rather than an error message, so models must be checked before export or manufacture.; Three.js forward rendering pipeline only, no deferred rendering support
  • They diverge on capability: SolveSpace covers Constraint solver, Three.js covers WebGL rendering.
  • Prices and features above were last checked on 1 September 2026.

Where they differ

Only the attributes on which SolveSpace and Three.js actually diverge.

Attributes where SolveSpace and Three.js differ
AttributeSolveSpaceThree.js
Pricing modelOpen source, no licence feefree
PlatformsWindows, macOS, LinuxWeb, macOS, Windows, Linux, iOS, Android
CategoryCADAR VR
FoundedUnknown2010

Identical on both: starting price (Free), free tier (Yes), user rating (Not yet rated).

What each one covers

Drawn from each product's published feature list. An absence here means we hold no record of it - not that the product lacks it.

Only in SolveSpace

  • Constraint solver
  • Solid modelling
  • Assemblies
  • Export formats
  • Cross-platform
  • Small footprint

Only in Three.js

  • WebGL rendering
  • Scene graph
  • Materials system
  • Animation system
  • WebXR
  • Post-processing
  • Physics
  • Loaders

What people use each for

The jobs each tool is most often brought in to do.

SolveSpace

  • Designing 3D printed parts on a machine that cannot run mainstream CADnot Three.js
  • Teaching constraint-based parametric modelling without buying licences for a classroomnot Three.js
  • Checking that a mechanical linkage moves as intended before cutting metalnot Three.js
  • Producing dimensionally accurate STEP or STL output from a small open source toolchainnot Three.js

Three.js

  • VR Gamingnot SolveSpace
  • AR Marketingnot SolveSpace
  • Virtual Trainingnot SolveSpace
  • 3D Visualizationnot SolveSpace
  • Immersive Experiencesnot SolveSpace

Where each one falls short

Documented limitations, not opinions. Every one is a constraint you would hit in normal use.

SolveSpace

  • The in-house geometry kernel fails on complex boolean operations and fillets, and the failure is sometimes silent bad geometry rather than an error message, so models must be checked before export or manufacture.
  • There is no proper drawing and dimensioning workflow, so manufacturing documentation has to be produced in another application.
  • Development is volunteer-led and intermittent; long gaps between releases are normal and there is no support contract available at any price.
  • Assembly-level import of external CAD is very limited, so it does not fit a supply chain that exchanges native or assembly-level models with suppliers.
  • The interface follows its own conventions rather than mainstream CAD ones, so existing SolidWorks or Fusion users spend time unlearning habits for a tool with a lower ceiling.

Three.js

  • Forward rendering pipeline only, no deferred rendering support
  • No built-in collision detection or spatial indexing, requiring external physics libraries
  • WebGL dependency means no support for non-WebGL environments

Pricing, plan by plan

SolveSpace

Free
  • SolveSpaceFree
    • Full application under the GPL
    • No seat limit
    • Windows, macOS and Linux builds

Three.js

Free
  • FreeFree
    • Full library
    • WebXR module
    • Examples

Which should you pick?

Choose SolveSpace if

  • You need constraint solver.
  • You want to start without paying.
  • You work on Windows, macOS, Linux.
  • You also want solid modelling.
SolveSpace review

Choose Three.js if

  • You need webgl rendering.
  • You want to start without paying.
  • You work on Web, macOS, Windows, Linux, iOS, Android.
  • You also want scene graph.
Three.js review

Questions people ask

Is SolveSpace or Three.js better?
Neither clearly leads. SolveSpace starts at Free and Three.js at Free, and user ratings are close enough to be indistinguishable. Choose on capability and platform support.
Which is cheaper, SolveSpace or Three.js?
SolveSpace starts at Free and Three.js at Free.
Does SolveSpace or Three.js run on more platforms?
SolveSpace runs on Windows, macOS, Linux. Three.js runs on Web, macOS, Windows, Linux, iOS, Android.
Can I use SolveSpace for free?
Both have a free tier, so you can try either at no cost before committing.
What is SolveSpace best used for?
SolveSpace is most often used for designing 3d printed parts on a machine that cannot run mainstream cad, teaching constraint-based parametric modelling without buying licences for a classroom, checking that a mechanical linkage moves as intended before cutting metal, producing dimensionally accurate step or stl output from a small open source toolchain. Of those, designing 3d printed parts on a machine that cannot run mainstream cad and teaching constraint-based parametric modelling without buying licences for a classroom are not what Three.js is typically brought in for.
What can SolveSpace do that Three.js cannot?
SolveSpace covers Constraint solver, Solid modelling, Assemblies, Export formats. Three.js covers WebGL rendering, Scene graph, Materials system, Animation system.

Answered from the vendors’ own pages

SolveSpace: Is it really free for commercial work?

Yes. It is released under the GPL with no licence fee and no seat limit. Support is community only.

Three.js: Is Three.js free to use?

Yes. Three.js is released under the MIT license, an open-source license that permits unlimited commercial and personal use with no licensing fees.

Source
SolveSpace: Can it replace Fusion 360 or SolidWorks?

No. It handles parts and simple assemblies well. Complex geometry, drawings and supply chain interoperability are outside its range.

Three.js: Does Three.js include physics simulation?

No. Three.js is a rendering library only. Physics, collision detection, and spatial indexing must be implemented with external libraries like Rapier, Ammo, or JoltPhysics.

Source
SolveSpace: What hardware does it need?

Very little. It runs on old laptops and small Linux machines where mainstream CAD will not start.

Three.js: Can I use Three.js for offline development?

Yes. Local development requires a local web server for CORS compliance. You can use npm with a build tool like Vite, or run a local Python server for development.

Source
Three.js: Does Three.js support WebXR for VR/AR?

Yes. Three.js documentation includes WebXR APIs for building VR and AR experiences in web browsers.

Source
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