Open it

slop-cad lives at https://slopcad.app. Open the link and it is running. There is nothing to install.

What your browser needs

Requirement	Why
WebAssembly	The constraint solver and the modelling kernel are compiled to WebAssembly and execute in the page.
WebGL 2	The 3D model view renders through WebGL. Without it the 2D sketcher still works and the Model button stays unavailable.
A current browser	Recent Firefox, Chrome, Edge, or Safari.

A mouse with a middle button and a scroll wheel makes navigation considerably easier. Panning in the sketch view is bound to the middle button, and orbiting in 3D wants a drag that a trackpad has to emulate.

On a tablet

It works. A mouse and a keyboard are still the better way in, but nothing here depends on having them.

The document panel starts put away on a screen this size, leaving the drawing the room; the chevron at the left edge brings it back, and the sidebar opposite it can go the same way. In the sketch, one finger draws and drags, two fingers pan and zoom together, and a press and hold is the right-click menu. In the model view, one finger orbits, two pan and zoom, and a tap picks a face.

A ten-inch screen is about the smallest that reads. On a phone the drawing area left over after the tool strip is too small to place anything accurately, and none of the panels are laid out for a column that narrow. The page will load, and there is not much you can do once it has.

Where your work goes

Nothing you draw leaves your machine. The solver and the kernel run inside the tab and there is no upload step.

Save is how work is kept. It writes a sketch.slop.json file to your usual downloads folder, and Open reads one back. That file is the copy you named, at the moment you chose, and it is the one that outlives the browser and can be carried to another machine.

Underneath that, the browser holds the document you have open and offers it back if the tab closes without you meaning it to. See saving.

The other things that survive a reload are interface preference: how wide the panels are, which ones you put away, which sections you left expanded, whether grid snapping was on, and which theme you chose.

Give it a first look

Press Example in the top bar. It loads a 40 x 25 mm rectangle that is already fully constrained, which is the quickest way to see what a finished sketch looks like. Clear puts you back to an empty document.

Clear asks for no confirmation and cannot be fully undone, so treat it as a decision rather than a way to tidy up.

Next

Build your first part takes the example and turns it into an exported solid.