If you're a designer, engineer, or hobbyist looking to create 3D models without breaking the bank, you're in luck. There are several free online CAD platforms that offer powerful tools for designing and modeling without the need for expensive software. Here are the top 5 free online CAD platforms to check out:

1. Tinkercad: Tinkercad is an easy-to-use, browser-based CAD platform that's perfect for beginners. It offers a range of tools for creating 3D designs, and it's free to use.

2. Onshape: Onshape is a professional-grade CAD platform that's available for free for non-commercial use. It's full-featured and offers collaborative design tools for teams.

3. FreeCAD: FreeCAD is an open-source parametric 3D CAD modeler that's great for creating complex designs. It's compatible with Windows, macOS, and Linux.

4. SketchUp Free: SketchUp Free is a popular 3D modeling platform that offers a free version for personal use. It's intuitive and easy to use, making it great for beginners.

5. Fusion 360 for Startups: If you're a startup, you can get access to Autodesk's Fusion 360 platform for free. It offers advanced design and engineering tools for creating 3D models.

These free online CAD platforms offer a range of features for designers and engineers to create 3D models and designs without the need for expensive software. Whether you're just getting started or need professional-grade tools, there's a free CAD platform for you. Try out one of these platforms and start creating your 3D designs today.