How to Create Parametric 3D Models Online for Free

Set up a small experiment you can verify

Open SolidCraft Online in a desktop browser with a mouse. The captures here use the English v0.23.0 editor on macOS with WebGL2. The first launch downloads the application; keep the tab open while it loads. A phone can be useful for reading this guide, but this test does not establish precise modeling on a touchscreen.

Start a new design and choose millimetres. If another part is open, download anything you need before replacing it. The target is intentionally simple: one rectangle, two driving dimensions and one extrusion. Its arithmetic gives you an independent check on whether the edit did what you intended.

Our verification constructs the geometry through the editor’s documented control API, then changes the sketch dimension through the actual interface. The commands are provided with the model files so the construction can be reproduced. The manual tool names below are checked against the pinned release; this is distinct from claiming a complete mouse-only creation session.[controls][sketching]

1. Draw a rectangle anchored to the origin

In the model workspace, choose Create Sketch and select the XY origin plane. In sketch mode, choose 2-Point Rectangle or its R shortcut. Place the first corner at the sketch origin, then place the opposite corner in the positive X/Y quadrant.

The first corner’s relationship to the origin matters. Two dimensions can define the size of a rectangle while leaving it free to move around. A coincident origin corner removes that extra movement. The rectangle’s horizontal, vertical and coincident relationships keep it rectangular as its dimensions change.

Keep the boundary as ordinary sketch geometry. Construction geometry is for reference and does not form the filled region you need for a solid. Look for one closed rectangular profile. A visual outline alone is insufficient if two endpoints only appear to meet or an edge is construction-only.[sketching]

2. Add the two driving dimensions

Choose Sketch Dimension or press D. Dimension a horizontal rectangle edge to 40 mm, then a vertical edge to 30 mm. Enter explicit units if the document is not already in millimetres. Avoid dimensioning both opposite edges to the same size; the rectangle’s relationships already determine those duplicate lengths.

A driving dimension instructs the solver to change the sketch. A driven or reference dimension reports a value determined elsewhere. In v0.23.0, if the existing constraints already determine a proposed dimension, the interactive tool adds it as a driven (reference) dimension, shown in parentheses with no editable value. Edit the original driving dimension to resize the sketch. If a constraint is refused, inspect the existing relationships before adding more.[sketching]

The verified model uses the automatically created dimension parameters. You do not need to define a separate named user-parameter table to complete this exercise. The essential result is a sketch that knows its two sizes and position, and can recompute when one size changes.

3. Extrude the closed profile by 10 mm

Choose Finish Sketch, then Extrude. Select the rectangle’s filled profile, use a one-sided distance of 10 mm, and choose a new-body operation. Confirm the feature and orbit the view to inspect the result.

You should now have one rectangular solid, a sketch and an extrusion in its construction history. If the extrusion tool finds no profile, return to the sketch and inspect closure and construction status. If it creates a surface or an unexpected region, check what you selected before changing the dimensions.

The check is 40 × 30 × 10 = 12,000 mm³. This clean geometry is a useful control case: a substantially different volume indicates different dimensions, more than one body, or an unintended feature. Save an original native copy before making the next revision.

4. Edit the sketch, then check the rebuild

Open the existing sketch for editing from its timeline feature. Double-click the horizontal 40 mm dimension, replace its value with 50 mm, confirm the entry, and finish the sketch. Edit the dimension on the existing rectangle; drawing a second rectangle or scaling the final mesh is a different operation.

The extrusion should rebuild to a 50 × 30 × 10 mm block. The height remains controlled by the extrusion, and the other sketch dimension remains 30 mm. Our actual UI edit uses the dimension’s text, confirms the value and finishes the sketch; inspection then reports one solid at 15,000 mm³.

Try Undo and Redo to compare the two revisions. Depending on the current editing state, entering or leaving sketch mode may add an undo step. Watch the actual dimension or geometry rather than assuming a fixed number of keyboard presses. The verification record checks both target volumes.

5. Download and reopen the editable revision

Use the site editor’s Download toolbar action to obtain the current .solidcraft design. The native File menu also offers a design download. Check your browser’s download location and keep the original and revised copies under distinguishable names.

Return to the online page and choose its native-file picker to open the revised download in a compatible editor. Confirm one solid, the sketch and the extrusion, then inspect the dimensions again. The provided revised file was downloaded and reimported in a new design before its screenshot was taken.

Saving depends on the browser. Chrome, Edge and Opera can use a local file picker and write back to the chosen file after permission is granted. Firefox and Safari keep ordinary saves in browser storage. File → Download design makes a separate backup in any browser; autosave and recovery remain in browser storage. Clearing site data can remove those browser copies.[files]

These files use native format 37 from v0.23.0. The older emergency editor cannot open this newer format. Keep an untouched original before upgrading files in future releases. Browser storage, an ordinary downloaded file and an optional cloud save have different recovery paths.[files][online]

An STL can carry a triangulated surface to another tool, but it does not preserve this editable sketch and extrusion. For the next exercise, keep the native file and follow the 3D-printing workflow to create a plate and check its exported mesh.

When the result does not match

If you are still choosing a tool, the free CAD shortlist explains account, privacy and workflow differences. For a broader introduction to the interface and sketch-to-solid concepts, continue with the beginner guide.

Keep the editable original

Files for this exercise

Common questions

A few things to know