Free Online CAD, No Download

What is free online CAD?

Free online CAD is design software that runs in your web browser instead of on your computer. There is no download, no plugin and no licence key; your designs save to the cloud, so you can open them on any device. Most free plans limit something, such as private files or exports.

Desktop CAD still means a large install, a licence that can cost thousands a year, and weeks of learning the interface. Browser CAD removes the install and the licence. The good ones also lower the learning curve, which is where most people give up.

Which kind of online CAD do you need?

Start from the job, not the tool. Online CAD falls into four kinds: block modellers for simple shapes and teaching, parametric CAD for precise mechanical parts, 2D editors for laser and plasma cutting files, and viewers for opening a file you were sent. AI CAD adds a fifth: describe the part.

Viewers and generators: the STEP viewer, the 3D file viewer for STL, OBJ and GLB, legacy IGES files, and the gear generator, which draws real involute gears from a tooth count and module. For flat parts, see DXF files for laser cutting, and for bent sheet metal, the bend allowance calculator.

Can you design a part online without learning CAD?

Yes. With PartWork.ai you describe the part in plain English, with its dimensions, and the AI builds editable 3D geometry. You do not need to know which feature comes first or how to constrain a sketch. You can then change it by asking, or by selecting a face and typing what you want.

Create a 50 mm cube with a 10 mm hole through the center
Add a 3 mm fillet to all edges

If you already know CAD, the familiar tools are there: Sketch, Extrude, Fillet, Chamfer and Hole. Select a face, click a tool, and the change applies to your selection. The Quick Start Guide walks through a first part both ways, and designing a bracket for 3D printing is a worked example.

What is free on PartWork.ai, and what uses credits?

Uploading and viewing CAD files in 3D is free, with no account needed. Designing a part, running a modelling step or downloading a file uses credits, and the cost shows before anything runs. New accounts get free trial credits; after that, credits come in packs of 50 for $4.99, about 10¢ each.

You see the credit cost before a step runs, so nothing is charged by surprise. CAD files up to 75 MB can be imported. Your designs and prompts are never used to train AI models and never sold. The full list of limits is in the FAQ.

Can online CAD export STEP and STL files?

Good browser CAD exports both, and that is the test of whether a tool is useful for real parts. PartWork.ai exports STEP for CNC machining and other CAD software, STL for 3D printing, and 3MF, the 3D printing format that carries units. It imports STEP, IGES, BREP, DXF, OBJ and STL.

Use STEP whenever you have the choice: it keeps exact solid geometry that any CAD program can edit, while STL is a mesh of triangles meant for slicers. See STL vs STEP for which to send where, and what a STEP file is.

Does online CAD work on a phone or tablet?

PartWork.ai does. Because it runs in the browser, the same app works on a desktop, a tablet and a phone, with touch controls to rotate and zoom the part. Start a part on your laptop and open it on your phone right where you left off.

Describing a part is easier on a phone than drawing one, because typing a sentence beats dragging a sketch with a finger. For checking a part on the shop floor, see viewing 3D parts on a phone.

When is desktop CAD still the better choice?

Desktop CAD is still better for large assemblies with hundreds of parts, for production drawings with full tolerancing, and for work that must stay offline. Browser CAD is best for single parts: brackets, plates, enclosures, spacers, adapters and gears, designed and exported in one sitting.

The geometry itself is not the compromise. PartWork.ai works in double precision, so a 10 mm hole is 10 mm in the exported STEP file. Check the units before you export: a part designed in inches exports in inches.

Can you turn a 2D drawing into a CAD model online?

Yes. If you have a PDF, PNG or JPG drawing of a part and need a 3D model, you do not have to redraw it. Upload it to PartWork.ai and get a STEP file checked against every view of the drawing, in minutes, from $29.99 per part. The check and the quote are free.

It suits legacy prints, obsolete parts and anything a machine shop or instant-quote site wants as STEP. See Drawing to STEP for prices and what it converts.

Frequently asked questions

Ready to design a part in your browser?

Open the Studio and describe your first part, or drop in a CAD file to view it free. There is nothing to install, and new accounts start with free trial credits.