If you need to access DWG files but don't have AutoCAD or other CAD software installed on your computer, there are several online tools that allow you to open and view these files for free. Here are some easy methods to open DWG files online:

1. AutoCAD Web App: Autodesk offers a web-based version of its popular CAD software, AutoCAD. With the AutoCAD Web App, you can open and view DWG files directly in your web browser without the need for any additional software.

2. FreeOnlineViewer: FreeOnlineViewer is a simple and easy-to-use online tool for opening and viewing DWG files. You can simply upload your DWG file to the website and view it instantly without any hassle.

3. A360 Viewer: A360 Viewer is another online tool provided by Autodesk for viewing DWG files. It allows you to upload your DWG file and view it in a web browser, with support for 2D and 3D drawings.

4. DWG TrueView: Although not entirely online, DWG TrueView is a free desktop application from Autodesk that allows you to open and view DWG files. It also provides the ability to convert DWG files to different versions for compatibility with older CAD software.

5. ShareCAD: ShareCAD is a web-based tool that allows you to open and view not only DWG files, but also other CAD file formats such as DXF and DWF. It provides a simple and intuitive interface for viewing drawings online.

These online tools make it easy and convenient to open and view DWG files without the need for expensive or complex CAD software. Whether you're a professional designer or someone who occasionally needs to access DWG files, these methods provide a hassle-free way to view AutoCAD drawings. Try them out and find the best solution that fits your needs!