- In many cases, an older release of AutoCAD can’t open a DWG file that’s been saved by a newer AutoCAD release. The table below shows the relationship between AutoCAD versions and their corresponding file formats.
- A newer release of AutoCAD can always open files saved by older versions. I have sample files dating back to 1984 that open in AutoCAD 2020.
- Some previous AutoCAD releases can open files saved by a subsequent version or two. As the following table shows, Autodesk changed the DWG file format every three years or so starting in 2000 but has leveled off recently so that drawings created in or saved by AutoCAD 2017 can be opened
- You can use the Save As option in a newer release to save a file to an older DWG format. In fact, AutoCAD 2020 can Save As all the way back to AutoCAD Release 14, in the last millennium (1997). In addition, you can save a file as a simple text-based DXF format as far back as Release 12 (1992). The table below shows which versions use which DWG file formats.
| AutoCAD Version | AutoCAD LT Version | DWG File Format |
| AutoCAD 2018-2020 | AutoCAD LT 2018-2020 | AutoCAD 2018 |
| AutoCAD 2013–2017 | AutoCAD LT 2013–2017 | AutoCAD 2013 |
| AutoCAD 2010–2012 | AutoCAD LT 2010–2012 | AutoCAD 2010 |
| AutoCAD 2007–2009 | AutoCAD LT 2007–2009 | AutoCAD 2007 |
| AutoCAD 2004–2006 | AutoCAD LT 2004–2006 | AutoCAD 2004 |
| AutoCAD 2000, 2000i, 2002 | AutoCAD LT 2000, 2000i, 2002 | AutoCAD 2000 |
| AutoCAD R14 | AutoCAD LT 1998, 1997 | AutoCAD R14 |
| AutoCAD R13 | AutoCAD LT 1995 | AutoCAD R13 |
| AutoCAD R11, R12 | AutoCAD LT R2 | AutoCAD R11 |
Earlier formats may not support all the features of later formats. AutoCAD does its best at translating, but some items may be lost or may not fully survive the round trip to an older AutoCAD release and back to the newer one.
So, do you have to use AutoCAD to produce DWG files? The answer is no. Several low-cost to no-cost programs claim to be compatible with AutoCAD’s DWG file format. They usually come with a few crunchy bits, however.- Because these programs have to reverse-engineer the file format, they are often one release behind AutoCAD’s current version.
- These programs usually don’t fully support all AutoCAD features because of copyright, patent, or perceived market size limitations. In particular, annotative objects, parametrics, and 3D models may not survive unscathed from a round trip to the other brand and back to AutoCAD.
- Yes, a line is a line and a circle is a circle in a DWG file, but the commands that you use in other programs to put them in the file may not operate in the same way.