These are browser-based gateways. You upload a DWG, they convert it server-side, you download a PDF or PNG.

If you are a developer or IT manager selecting a gateway solution, consider this matrix:

| Use Case | Recommended Gateway | Why | | :--- | :--- | :--- | | Building a new CAD app | ODA Drawings SDK | Industry standard, supports 2025 DWG, includes .NET & C++ APIs | | Web-based viewer | Autodesk Platform Services (formerly Forge) | Cloud-native, but requires subscription | | Open-source project | LibDWG (GNU) | Limited features (no write support, some entities missing) | | Batch conversion server | Any ODA-based converter (e.g., Teigha Converter) | Free, command-line driven | | Drafting on Linux/macOS | BricsCAD’s internal gateway | Highest fidelity for non-Windows platforms |

Gateways are often used in batch processors or BIM coordination tools (like Navisworks alternatives). They need to handle massive files (100MB+) and sheets with thousands of external references (Xrefs) efficiently.

DWG formats change every few years (from AutoCAD R14 to 2025). A good gateway supports reading older versions (e.g., R12) and writing to multiple modern versions (2004, 2007, 2013, 2018, etc.).