How-to guide · how to convert an old dwg to a current version

How to convert an old DWG to a current version

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By Sumana Kumar · Published 9 Apr 2022 · Updated 2 Mar 2024

DWG is not a single fixed format — it has evolved through generations, each tied to a range of AutoCAD releases. An old drawing saved in a legacy format usually opens fine in current AutoCAD, but converting it to the current DWG version lets it take advantage of newer features, keeps a file set consistent, and avoids the slow load and odd behaviour that very old files sometimes show. The reverse is just as common: saving down so a colleague on an older seat can open your work.

Converting between versions is simply a matter of choosing the right format in SAVEAS — there is no special 'convert' command for a single file. This guide covers upgrading an old DWG, downgrading for compatibility, the DWG version families you will meet in the dropdown, and how to batch-convert a whole folder at once. It is the routine you reach for whenever a file's age, not its content, is causing trouble.

Understanding DWG version families

AutoCAD's DWG format has changed in steps, and several consecutive releases share each format. When you save, the file format dropdown lists named DWG versions — older and newer 'AutoCAD Drawing' formats — rather than year-by-year. A drawing saved in a newer format will not open in a seat too old to read it, which is the whole reason version juggling exists.

The practical takeaway: newer AutoCAD reads old formats freely, but old AutoCAD cannot read newer ones. So you upgrade an old file simply to modernise it, but you downgrade a new file specifically so an older seat can open it. Knowing which way you are going tells you which format to pick in the dropdown.

Step 1 — Open the old drawing and run SAVEAS

Open the legacy DWG. Type SAVEAS (or use the application menu, Save As) to open the Save Drawing As dialog. At the bottom is the crucial control: the 'Files of type' dropdown. This is where you choose the DWG format version the file will be written in.

Saving over the file with SAVE keeps its existing format; only SAVEAS lets you change the version. So even if you are saving to the same filename, use SAVEAS when you want to change the format, and watch the 'Files of type' field — that, not the filename, controls the version.

Step 2 — Choose the target DWG format

In the 'Files of type' dropdown, pick the DWG format you want. To modernise an old file, choose the most recent 'AutoCAD Drawing' format your software offers. To make a file openable on an older seat, choose the older format that seat can read — when in doubt about a recipient's version, picking an older DWG format is the safe, broadly-compatible choice.

Type or confirm the filename, choose a folder, and click Save. AutoCAD rewrites the drawing in the chosen format. The geometry is unchanged; only the file's internal format version differs. Keep the original if you are downgrading, in case the older format drops a newer feature the drawing used.

Step 3 — Set a default save format (optional)

If you constantly save to a particular DWG version — for example because your office standardises on a format everyone can open — set it as the default so you do not have to choose every time. In Options, on the Open and Save tab, set 'Save as' to your preferred DWG format. Every subsequent SAVE and SAVEAS then defaults to it.

This is worth doing in mixed environments where some seats are older. Standardising the default save format on the lowest version anyone needs means files are openable across the whole team without thinking about it on every save.

Batch-converting a whole folder

Converting files one at a time is fine for a handful, but for a folder full of legacy drawings, batch it. AutoCAD's bundled DWG conversion utility (DWG Convert) lets you build a list of drawings and write them all out to a chosen DWG version in one run, with options to also purge and audit each file along the way. You point it at the files, pick the target format, and let it process the lot.

For pure format conversion outside AutoCAD, the free ODA File Converter is a popular standalone tool: it converts whole folders of DWG and DXF between versions without opening each file. Either route turns a tedious manual job into a single batch operation — useful when modernising an old project archive.

Compatibility pitfalls to watch

Downgrading carries a real risk: features introduced after the target format may not survive the trip. Saving a drawing that uses newer object types down to an old format can turn those objects into proxies or simplify them, so always keep the original and check the downgraded file before relying on it.

Upgrading is generally safe — newer formats are supersets — but do not assume converting an old file magically fixes problems inside it; corruption or bad geometry survives a version change. Pair conversion with AUDIT and PURGE for a genuinely clean result. And confirm the recipient's actual version before downgrading; guessing too new locks them out, while too old is merely cautious.

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Questions

Frequently asked

How do I save a DWG to a newer or older version?+

Use SAVEAS and change the 'Files of type' dropdown to the DWG format you want. Pick the newest format to modernise an old file, or an older format so an older AutoCAD seat can open it. Plain SAVE keeps the existing format, so SAVEAS is required to change versions.

Will my drawing open in an older version of AutoCAD?+

Only if you save it in a format that older version can read. Newer AutoCAD opens old formats freely, but old AutoCAD cannot read newer DWG formats. To share with an older seat, SAVEAS to an older DWG format that seat supports.

How do I convert many DWG files at once?+

Use AutoCAD's bundled DWG Convert utility to batch a list of drawings to a target format (with optional purge and audit), or the free standalone ODA File Converter to convert whole folders of DWG and DXF between versions without opening each file.

Is anything lost when I save a DWG down to an older version?+

It can be. Features and object types newer than the target format may simplify or turn into proxies on the way down. Always keep the original and check the downgraded file. Upgrading to a newer format is generally safe since newer formats are supersets.

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