AutoCAD File Types: Tuesday Tips With Frank


This week’s Tuesday Tips installment is an important topic involving various files. During an editing session, AutoCAD creates several files along with your DWG (or DWT or DWS – they’re all the same thing with a different extension). Some are temporary and go away when you exit the file; others do not. Here we’ll explore these different AutoCAD file types.

Easy Ones to Find

By default, this first group of files is saved in the same folder as your DWG file. When the drawing is open, AutoCAD creates lock files with DWL and DWL2 extensions alongside the DWG. You may not see them, as they are set to be hidden. You can turn on hidden files with the control shown below. They are used in conjunction with the WHOHAS command.

Screenshot of AutoCAD and how to find hidden items and file name extensions

This is also where you’ll find the BAK backup file if enabled. Each time you perform a SAVE, a QSAVE, or quit and save, an exact copy of the drawing file prior to that save is created with a BAK extension. The feature is on by default, and you can find it in the Open and Save tab of the Options dialog (it controls the ISAVEBAK system variable).

Screenshot of where to find BAK file in AutoCAD

Next comes the temporary files that are usually written to your temp file folder. This includes the Automatic Save File Location. Where is that, you ask? There are a couple of ways to find the folder. Again, expand the Automatic Save File Location entry from the Options dialog and Files tab. Highlight and copy the path to your clipboard, then paste it into the address bar of a file explorer window.

Screenshot of Automatic Save File Location in AutoCAD

Or, you can take the easy route and type %TEMP% into the address bar, which will take you right to it. If you don’t keep it cleaned out, you’ll probably see thousands of files there, mostly with all kinds of extensions, many of which are TMPs or some files or folders with no extensions. But somewhere in there, if the autosave feature has been invoked in your drawing session, there will be a file that consists of your drawing’s file name, followed by some seemingly random characters and an extension of SV$. That’s your autosave file.

It’s intended to be temporary, as it will be deleted if you exit your drawing properly. But, if you exit thanks to a crash of some kind, it will remain. Similar to the BAK file, it’s a copy of your file when the autosave was invoked. You could copy it somewhere and rename the extension to DWG, and you’d be good to go. Same with the BAK file. Like the backup creation, autosave is turned on by default and set to 10 minutes (the SAVETIME system variable). That control is in the same place as the BAK file creation control in the Options dialog.

Drawing Recovery Manager

OK, those are the important AutoCAD file types I wanted to cover today. They might just save you a lot of lost work someday, but who wants to remember secret codes, odd locations, name changes, or how to show extensions and hidden files in your file explorer? Back in my early days, when we worked mainly with ones and zeros, we had to know this stuff. But today, there’s an easier way. It’s called the Drawing Recovery Manager.

Screenshot of Drawing Recovery Manager in AutoCAD

If AutoCAD detects that it had previously terminated improperly, you’ll be presented with the Drawing Recovery Manager palette upon restarting it. It will contain an expandable list of all the files that were open when the crash occurred, with each entry containing all the available file types.

You may get the drawing file itself, the BAK, the SV$, or if you got prompted to save before the exit, you’ll get a file with _RECOVER appended. These files will be listed in the order that they were last saved.

Screenshot of Drawing Recovery Manager palette in AutoCAD

The Details panel in the middle of the palette gives you the file’s location and the date and time stamp. Below that, you’ll get a thumbnail preview, if available. It is all handy for you to decide which save file is the one you want to use. And when you decide, now it’s just a matter of right-clicking and selecting Open.

Remember those hidden lock files? If you use the Drawing Recovery Manager, it will handle those for you, as they’ll be left over in case of a crash. If you decide to recover the files manually, you’ll have to delete those, or your file will want to open as read-only—another good reason to do things the modern way.


Yes, the modern way is preferred. But what if the crash left your system unable to access AutoCAD? These things always happen at the worst time, and if you could only recover your work, a co-worker could take over. What a great time to know how to do it manually. Knowing about these important AutoCAD file types and how to use them just might save the day for you sometime. Let’s hope that’s never the case, however.

More Tuesday Tips

Check out our whole Tuesday Tips series for ideas on how to make AutoCAD work for you. Do you have any favorite AutoCAD tips? Tell us in the comments!

Frank Mayfield

Frank has worked in various design and CAD Management roles with AutoCAD and Autodesk software since 1986 (v2.62). He is currently a Design Technology Consultant in Tulsa, OK. He also serves as Vice President on the AUGI Board of Directors and is a member of numerous Autodesk user panels. As a top-rated mentor for trial users of AutoCAD 2018 and AutoCAD LT 2018, he has provided live, real-time guidance and support for over 2,500 new users in more than 50 countries worldwide. He currently serves on the AUGI Board of Directors and is a member of numerous Autodesk user panels.

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