Explainer · what is a sv$ file autocad

What is a SV$ autosave file, and how do I recover from one?

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By Sumana Kumar · Published 23 Jan 2025 · Updated 22 Sept 2025

A SV$ file is AutoCAD's automatic save file — a periodic snapshot of the drawing you are working on, written quietly in the background so that a crash or power cut does not cost you the whole session. The unusual extension (the letters SV followed by a dollar sign) is just AutoCAD's marker for 'temporary autosave data', and the file is a complete DWG inside, only renamed.

Most of the time you never notice these files. AutoCAD creates them on a timer, overwrites them as you keep working, and tidies them up when you close the drawing normally. You only go looking for one after something goes wrong: AutoCAD froze, the machine rebooted, or you closed without saving and realised too late. In that moment the SV$ can hand back most of your work.

Understanding what the file is, where it lives, and how to turn it back into a usable DWG takes the panic out of a crash. It is one of the simplest safety nets in AutoCAD, and it is on by default.

What the SV$ file actually is

A SV$ is a full copy of your drawing's database at the moment of the last automatic save. It is not a fragment or a diff — open it and you get the whole drawing as it stood when AutoCAD last wrote the snapshot. The dollar-sign extension exists so the file is obviously temporary and so it does not clutter your normal DWG listings.

AutoCAD names it after the original drawing with some extra characters and a number, for example 'MyPlan_1_1_1234.sv$'. The leading part is your drawing name, which is how you tell SV$ files apart when several drawings were open at once. Because it is a true DWG inside, recovery is just a matter of renaming or opening it — there is no special converter involved.

How often AutoCAD writes one

Autosave runs on a timer you control. The SAVETIME system variable sets the interval in minutes — a common default is around ten minutes, and many people shorten it to five for heavy or risky work. AutoCAD only writes the snapshot when you have made changes and are not in the middle of a command, so it never interrupts you mid-action.

There is a trade-off. A short interval means less lost work after a crash but slightly more frequent pauses to write the file; a long interval is smoother but risks losing more. For most furniture and architectural drawing, five to ten minutes is a sensible balance. The autosave clock only counts working time, so a drawing you leave open but untouched is not constantly re-saved.

Where to find SV$ files

By default the SV$ goes to your system's temporary folder, not next to the DWG. The exact path is set by the SAVEFILEPATH system variable, and you can read or change it in OPTIONS under the Files tab ('Automatic Save File Location'). On Windows the default is usually the user Temp folder, which is why people sometimes cannot find their autosave — they are looking in the project folder instead.

A useful habit after a crash: type SAVEFILEPATH at the command line to print the folder, then browse straight to it. If you want autosave files kept somewhere obvious and persistent, point SAVEFILEPATH at a dedicated folder rather than Temp, because Windows can clear the Temp folder and take old SV$ files with it.

Recovering a drawing from a SV$

There are two reliable routes. The simplest is to find the SV$ in its folder, rename its extension from .sv$ to .dwg, and open it — it is a normal drawing once renamed. Give the renamed copy a clear name like 'MyPlan_recovered.dwg' so you do not confuse it with the original.

The other route is AutoCAD's Drawing Recovery Manager (RECOVERYMANAGER), which usually appears automatically the next time you launch AutoCAD after a crash. It lists the drawings that were open, shows the available backups including the autosave, and lets you open the best one with a click. Whichever route you take, immediately do a proper SAVE to a real .dwg in your project folder, then carry on. Treat the recovered file as the new master and discard the broken original only once you have confirmed the recovery is good.

SV$ versus BAK files

AutoCAD keeps two kinds of safety file and they are easy to mix up. The SV$ is the autosave snapshot, written on the timer to a temporary folder. The BAK is the backup of your last manual save: every time you press Save, AutoCAD renames the previous version of the file to .bak and writes the new one as .dwg, keeping the BAK right next to the drawing.

So they protect different moments. The BAK gives you back the state at your previous deliberate save; the SV$ gives you back the state at the last automatic snapshot, which may be more recent if you have been working for a while without saving. To recover from a BAK, rename it to .dwg just as you would an SV$. Knowing both exist means you usually have at least one good fallback after any mishap.

Keeping autosave working for you

A few settings make autosave dependable. Confirm ISAVEBAK is on so BAK files are actually created, keep SAVETIME at a value you are comfortable losing (five to ten minutes), and make sure SAVEFILEPATH points somewhere that does not get wiped. Check now and then that the autosave folder is not full or read-only, because a failed write defeats the whole purpose.

Autosave is a safety net, not a save strategy. It does not replace saving to your project folder, version-stamping milestone files, or backing the project up off the machine. Think of the SV$ as the thing that rescues the last few minutes after a crash, while your real protection is regular manual saves and a backup routine. Used together they mean a hung AutoCAD costs you minutes, not days.

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Questions

Frequently asked

How do I open a SV$ file?+

Rename the file's extension from .sv$ to .dwg and open it like any drawing, or use the Drawing Recovery Manager which lists autosave files and opens them for you. The SV$ is a complete DWG inside, so no conversion is needed.

Where does AutoCAD save SV$ files by default?+

In the location set by the SAVEFILEPATH variable, which is usually your system Temp folder. Type SAVEFILEPATH at the command line to print the exact path, or change it under OPTIONS > Files > Automatic Save File Location.

How is a SV$ different from a BAK file?+

The SV$ is the timed autosave snapshot kept in a temp folder; the BAK is the backup of your previous manual save, kept beside the drawing. The autosave may be more recent if you have worked a while without saving, so check both after a crash.

How often does AutoCAD autosave?+

On the interval set by the SAVETIME variable, commonly around ten minutes by default. You can shorten it for risky work, but autosave only triggers when you have made changes and are not mid-command, so it never interrupts an action.

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