SolveSpace is a free and open-source 2D/3D constraint-based parametric computer-aided design (CAD) software that supports basic 2D and 3D constructive solid geometry modeling.

By default, SolveSpace utilizes its own CAD file format called .slvs for model storage.

It is possible to export models as a whole or in part to various formats such as PDF, SVG, or Encapsulated PostScript (EPS).

[2] A previous software package called SketchFlat, also developed by Westhues, was replaced by SolveSpace.

[13] SolveSpace v3.0 is able to export 2D sketches and surfaces into DXF/DWG (AutoCAD version 2007), PDF, SVG, EPS, and HPGL file formats.

SolveSpace is able to export models in STEP, STL, and G-code for reuse in third-party CAM software.

Users can make it active and draw basic primitives such as lines, circles, arcs, dots, and other points of references on the workplane, and constrain them to specific dimensions and relations.

Every group in SolveSpace encapsulates an action applied to the specified sketch created for every 3D operation, such as an extrusion, rotation, or translation.

As of v2.1., SolveSpace reference lists a disclaimer on limited support for NURB-surface Boolean operations which may occasionally fail.

[22] A 2013 article and interview with the main developer published in Libre Graphics World has praised SolveSpace for its small executable file size, advanced constraints solver, and output formats.