Upload two versions once
Upload A and B; the pair remains fixed until you start a new comparison. STEP pairs calculate red/blue solid differences automatically. Other 3D formats use visual side-by-side, overlay or A/B views.
CADProps · CAD tools
Compare CAD Files Online: STEP Geometry & Properties
Compare two 3D models visually and inspect their properties. STEP pairs additionally support automatic solid differences.
No account required
Temporary workspaceCAD processingBefore you use the result
Know what you are looking at.
Compare two 3D models visually and inspect their properties. STEP pairs additionally support automatic solid differences.
Preserve coordinates
No automatic alignment is performed. Centering is a display option, not a geometric registration.
Know the geometry
Mesh results are approximate; STL/OBJ assume mm. Do not compare physical dimensions before verifying source units. DWG supports separate 2D previews, without overlay or solid differences.
A reproducible example
Comparing two copies of the generated block produces zero added/removed volume and 24,000 mm³ common volume at the default 0.001 mm Boolean tolerance.
Repository-generated samples are synthetic test models. Verify your own model's units and geometry before using results.
Questions about this task
Know the limits.
Which inputs support solid differences?
Two valid closed STEP models can produce A-only, B-only and common material. Other supported 3D inputs provide visual comparison.
Does comparison align my models?
No. Boolean comparison uses source coordinates. Display centering is not geometric registration or manufacturing tolerance certification.
Are my files uploaded?
Selecting a file starts temporary server processing. Access is limited to your guest session. The entry shows configured retention and files can be deleted earlier.
Related reading
Checks that help with this file.
Versions & reviewCAD Versions vs Revisions: Track Models and Exports
Keep upload history, engineering revision labels and converted files separate so a new export does not masquerade as a design change.
Read the guide →Versions & reviewCompare CAD Revisions: Geometry and Property Checks
Use fixed versions, explicit units and a deliberate alignment method before interpreting overlays or property differences.
Read the guide →Versions & reviewShare a Fixed CAD Revision: File and Version Checklist
Pin a shared model or comparison to an explicit version, check recipient permissions and handle replacements without silent updates.
Read the guide →