"I tried to open a DWG from a client and got: 'The drawing was saved in a newer format and can't be opened.'" It's one of the most common AutoCAD headaches. The cause is simple: a DWG saved in a newer version of AutoCAD can't be opened in an older one (DWG is forward-incompatible).

This guide explains why that happens and shows you how to save or convert a drawing to a lower (older) DWG version—both with AutoCAD and without it.

目次

• Why an Older AutoCAD Can't Open the File
• Method 1: Save Down Inside AutoCAD (SAVEAS)
• Method 2: Convert Online, Without AutoCAD
• Which Version Should You Target?
• FAQ
• Lower a DWG's Version Right in Your Browser with DARE

Why an Older AutoCAD Can't Open the File

AutoCAD's DWG save format is updated every few years, and a file saved in a newer format simply won't open in an older AutoCAD. The rough mapping of formats to versions:

DWG format	Opens in AutoCAD versions
AutoCAD 2018 format	2018 and later
AutoCAD 2013 format	2013–2017
AutoCAD 2010 format	2010–2012
AutoCAD 2007 format	2007–2009
AutoCAD 2004 format	2004–2006

So a DWG saved by the latest AutoCAD (2018 format) won't open in AutoCAD 2017. The fix is for the sender to "save down" to an older format. That's exactly what "convert to a lower version" means.

Method 1: Save Down Inside AutoCAD (SAVEAS)

If you have AutoCAD, it's just a matter of choosing the format in Save As:

1. Type SAVEAS on the command line and press Enter (or use Save As).
2. In the Save Drawing As dialog, open the Files of type dropdown.
3. Pick the format that matches the recipient (e.g., for AutoCAD 2016, choose AutoCAD 2013/LT2013 Drawing (*.dwg)).
4. Save. The file will now open in the older AutoCAD.

To avoid doing this every time, set the default: OPTIONS → Open and Save tab → "Save as" default format, and choose an older format. Every save will then default to that lower version.

Method 2: Convert Online, Without AutoCAD

If you don't have AutoCAD—or you use a compatible CAD (ZWCAD, GstarCAD, etc.) that can't open the new format—a browser-based DWG version converter is the quickest route:

1. Open an online service that supports DWG version conversion.
2. Upload the DWG (or DXF) file.
3. Choose the target DWG version (e.g., 2013, 2010).
4. Run the conversion and download the lower-version DWG.

No software to install, and you can open the file you received right away. If you have many files, a service with batch conversion can process them all at once.

Which Version Should You Target?

Match the recipient's AutoCAD version whenever you can. If you don't know it, the AutoCAD 2013 format is a safe middle ground—it opens in 2013–2017 and is supported by most compatible CAD apps too. Don't go needlessly old (e.g., 2004 format), or objects created with newer features may be exploded or simplified. The rule of thumb: the newest format that the recipient can still open.

If you actually received the drawing as a PDF and need DWG, that's a format conversion, not a version downgrade. → How to Convert PDF to DWG

FAQ

Q. Can I lower the version without AutoCAD?
A. Yes. An online DWG version converter will save the file down to an older version with no software to install.

Q. Can I restore a downgraded DWG back to the newer version?
A. You can re-save it in a newer format, but data lost during the downgrade (newer-feature objects) won't come back. Keep the original file to be safe.

Q. Does converting to DXF make the version irrelevant?
A. No. DXF also carries a version on save. It's more portable, but if the recipient is on an old setup you still need to choose a lower DXF version.

Lower a DWG's Version Right in Your Browser with DARE

DARE is a cloud CAD conversion service that runs entirely in your browser—no software to install. It handles DWG version downgrades (save down), PDF to DWG / DXF, and DWG ⇔ JWW, all online.

When a file is "saved in a newer format and won't open," or you need to match an older CAD, just try DARE's Free CAD Converter and you're done.