What Is a DWG File?

DWG files are drawings used by CAD programs

What to Know

  • A DWG file is a drawing created and used by AutoCAD.
  • Open one with AutoCAD or Design Review; free options include DWG TrueView and Autodesk Viewer.
  • Convert from DWG to PDF, JPG, and more at Zamzar.

This article explains what a DWG file is, how to open one, and how to convert one to a different file format, such as PDF, DXF, DGN, STL, and lots of others.

What Is a DWG File?

A file with the .DWG file extension is an AutoCAD drawing. It stores metadata and 2D or 3D vector image drawings that can be used with CAD programs.

This format is compatible with lots of 3D drawing and CAD programs, which makes it easy to transfer drawings between programs. However, because there are numerous versions of the format, some DWG viewers can't open every type.

DWG Files

DWG is also short for some tech terms that have nothing to do with a file format, like domain work group and device working group.

How to Open a DWG File

Autodesk has a free DWG file viewer for Windows called DWG TrueView. They also have a free online viewer called Autodesk Viewer that will work with any operating system.

Of course, the full Autodesk programs—AutoCAD, Design Review, and Fusion 360—recognize this format, too.

Some other DWG file viewers and editors include ABViewer, CorelCAD, DoubleCAD XT, ArchiCAD, eDrawings Viewer, BricsCAD, and DWG DXF Sharp Viewer. Dassault Systemes DraftSight is another one for Mac, Windows, and Linux.

How to Convert a DWG File

Zamzar can convert DWG to PDF, JPG, PNG, and other similar file formats. Since it's an online DWG converter, it's much quicker to use than one you have to install to your computer. However, it's only the best option if the file isn't too large, since anything really big will take a long time to upload/download.

DWG conversion with Zamzar

Another free converter is Filestar. This one gets installed to your computer, and it supports lots of export formats, including PNG and other images, plus DXF, DWF, CMX, and CGM.

Other DWG files can be converted with the viewers mentioned above. For example, DWG TrueView can convert DWG to PDF, DWF, and DWFX; DraftSight can save to DXF, DWS, and DWT for free; and DWG DXF Sharp Viewer can export DWGs as SVGs.

Newer DWG file formats can't open in older versions of AutoCAD. See Autodesk's instructions on saving a DWG file to an earlier version, like 2000, 2004, 2007, 2010, or 2013. You can do it with the free DWG TrueView program through the DWG Convert button.

Microsoft has instructions on using a DWG file with Microsoft Visio. Once it's opened there, the file can be converted to Visio shapes. You can also save Visio diagrams to the DWG format.

AutoCAD should be able to convert the file to other formats like STL (Stereolithography), DGN (MicroStation Design), and STEP (STEP 3D Model). However, you might get a better conversion to the DGN format if you use the MicroStation software.

TurboCAD supports those formats, too, so you can use it to save the DWG file to STEP, STP, STL, OBJ, EPS, DXF, PDF, DGN, 3DS, CGM, image formats, and several other file types.

Still Can't Open It?

If your file doesn't open after following the suggestions described above, check the file extension one more time. You might be dealing with a completely different file extension. Especially if you're not familiar with CAD software, there's little chance you're really dealing with this specific file type.

For example, maybe your file really ends in OWG. Although it looks quite similar to DWG, they're really thesaurus files used by a data scraper program called Outwit.

Another example of a similar looking extension that is unrelated to any of the formats described on this page is BWG. It's instead an audio file used by BrainWave Generator. Attempting to open one in a CAD program would definitely throw an error message.

Other AutoCAD Formats

As you can tell from above, there are several CAD formats that can hold 3D or 2D data. Some of them look an awful lot like ".DWG," so it can be confusing how they differ. However, others use totally different file extensions but are still used within the AutoCAD program.

DWF files are Autodesk Design Web Format files that are popular because they can be given to inspectors who have no knowledge of the format or CAD programs. The drawings can be seen and manipulated, but some of the information can be hidden away to prevent confusion or theft.

Some versions of AutoCAD use DRF files, which stands for Discreet Render Format. These are made from the VIZ Render application that comes bundled with some older versions of AutoCAD. Because this format is so old, opening one in AutoCAD might make you save it to a newer format like MAX, for use with Autodesk 3DS MAX.

AutoCAD also uses the PAT file extension. These are vector-based, plain text Hatch patterns used for storing image data for creating patterns and textures. PSF files are AutoCAD PostScript patterns.

In addition to filling in patterns, AutoCAD uses Color Book files with the ACB file extension to store a collection of colors. These are used to paint surfaces or fill in lines.

Text files that hold onto scene information created in AutoCAD are saved with the ASE file extension. These are plain text files so that they're more easily used by similar programs.

Digital Asset Exchange files (DAEs) are used by AutoCAD and a number of other similar CAD programs to exchange materials between the applications, like images, textures, and models.

  • What is the difference between a DWG file and a DGN file?

    DGN files are the default format for MicroStation, the 2D and 3D modeling software from Bentley Systems, while DWG is the native format for other CAD programs such as AutoCAD. You can open DGN files created or edited in MicroStation in AutoCAD. MicroStation also supports AutoCAD DWG files.

  • What is the difference between DWG and DWT files?

    DWT files are AutoCAD template files. You can customize DWT files with preferred settings and presets and save work in the DWG format to use in computer-aided drafting (CAD) programs such as AutoCAD.

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