A Tinkercad or Onshape alternative that keeps your designs on your computer

If you are learning 3D design or teaching it, use Tinkercad: it is free and made for exactly that. If you need assemblies, fillets on a solid’s edges or drawings made from your parts, and you are content for your work to live in a vendor’s cloud, Onshape is the fuller program. The Engineering Suite is for the person between the two: parametric parts with a constrained sketcher, variables, STEP in and out, and preparation for a 3D printer, with every design kept in your browser and in files on your own disk. It is part of OBSCURA Pro, not free.

Start with what Tinkercad gets right

Tinkercad is a free web app from Autodesk for 3D design, electronics and coding. You drag shapes onto a work plane, make some of them holes, and group them, which is about the quickest way there is to a first printable object. Its own site calls it free with “no strings attached”, and it has classes for schools.

It asks you to sign in, with a Google, Apple or Microsoft account or one of Tinkercad’s own, and your designs are kept in that account. If that suits you and the shapes-and-holes way of working does what you need, there is no reason to pay for anything else, and it would be dishonest to invent one.

And what Onshape gets right

Onshape is full professional CAD in a browser. Its own help pages cover fillets, shells and lofts, sheet metal, assemblies built with mates, and drawings, none of which the Engineering Suite has yet. It describes itself as cloud-native: your documents live on its servers rather than in files on your disk.

Its Free plan is for hobbyists and non-commercial use only, and every document made on it is public: other Onshape users can see and copy it, and by Onshape’s terms may use it. For private documents its Standard plan is $1,500 per user per year and Professional $2,500. If you design for a living as part of a team, those prices buy a great deal.

Side by side

What each says about itself, as checked on 28 September 2026. Prices are in US dollars and change; check them before you decide.

Sources, as read on 28 September 2026: Tinkercad’s home page and help centre (sign-in, importing and exporting), and Onshape’s pricing page, its explanation of plans and data ownership, its terms of use and its help pages. Where a cell says “not compared here”, it is because we did not check it, not because the answer is no.

What the Engineering Suite adds to Tinkercad

• Dimensions you can change later. A part is a history of features built from sketches, and every number in it can be a variable: make the plate w wide and its holes w/2 - inset from the middle, change w, and the whole part follows.
• A sketcher with constraints. Twelve kinds, from coincident and tangent to symmetric, solved by FreeCAD’s solver, with the degrees of freedom left counted and any conflict named.
• STEP, both ways. A part from a supplier or another CAD program opens as a solid, and a part made here goes to a machine shop as a STEP file. (It writes curved faces as flat facets; the product page says why.)
• Measured and weighed. Distances between faces, edges and hole centres, a section through the part, and its volume, surface area and mass in ten materials, with the centre of mass and inertia.
• Ready for a printer. A face laid on the bed, overhangs that would need support coloured, and a part too big for the bed split into pieces with holes for alignment pins, packed onto plates as 3MF.

What Onshape has that it does not

• Fillets and chamfers on a solid’s edges, shells and lofts. The Engineering Suite rounds 2D corners in a sketch and the edges of a box, and makes solids from extrudes, revolves, primitives and booleans.
• Assemblies with mates. A part here can hold several bodies and check them for interference, but separate parts cannot be joined with mates.
• Drawings from parts, and sheet metal. Foundry makes 2D drawings, but does not project views from a 3D part.
• Exact curved surfaces. The kernel here (manifold, the library OpenSCAD uses) works on exact booleans of fine meshes, so a STEP it writes carries a cylinder as a ring of flats.

Where your designs live, and what that asks of you

The geometry is worked out in your browser, in WebAssembly, on your own processor. Each part is kept in the browser’s own storage for this site as it changes, with versions taken every few minutes and ones you name, and a part a crashed tab left behind is offered back. Nothing about the design reaches this site’s server; the only thing it ever sees is the Pro key.

That puts the backups on you. Clearing the browser’s data for the site clears the parts kept in it, so save the ones that matter as project files, as you would with any desktop program. In Chrome, Edge and Opera, Save writes back to the file you opened.

It keeps working with the network switched off once it has been opened with a Pro key, and checks with the network when there is one, so a cancelled plan stops working the next time it is online.

What it costs

The Engineering Suite is part of OBSCURA Pro: $15 a month or $144 a year, with 7 days free first, and a $5 day pass or a $9 week pass for a single job. The same plan covers Foundry for 2D drawings, the Photo Editor, the Sovereign Suite and saving in every other tool on the site. There is no free version with features held back: without Pro, the page shows the suite and asks for a plan.

See it before you pay. The Engineering Suite’s page shows it at work, lists what it cannot do yet, and offers the example part as STL and 3MF to open in your slicer.