Free DWG version checker
What AutoCAD version is my DWG file?
Drop a DWG to see which AutoCAD release saved it and the oldest AutoCAD that can open it. Caddis then test-opens the file to confirm it can be viewed. DXF, STEP, IFC, STL and PLY files work too.
DWG version codes and AutoCAD releases
Several AutoCAD releases share one file format, so a DWG's version names the format, not the exact release that saved it. Every AutoCAD and AutoCAD LT release opens its own format and everything older.
| Version code | DWG format | Saved by |
|---|---|---|
AC1032 | AutoCAD 2018 format | AutoCAD 2018 and later (and matching LT releases) |
AC1027 | AutoCAD 2013 format | AutoCAD 2013 through 2017 (and matching LT releases) |
AC1024 | AutoCAD 2010 format | AutoCAD 2010, 2011 and 2012 (and matching LT releases) |
AC1021 | AutoCAD 2007 format | AutoCAD 2007, 2008 and 2009 (and matching LT releases) |
AC1018 | AutoCAD 2004 format | AutoCAD 2004, 2005 and 2006 (and matching LT releases) |
AC1015 | AutoCAD 2000 format | AutoCAD 2000, 2000i and 2002 (and matching LT releases) |
AC1014 | AutoCAD Release 14 | AutoCAD Release 14 and AutoCAD LT 97/98 |
AC1012 | AutoCAD Release 13 | AutoCAD Release 13 |
AC1009 | AutoCAD Release 11/12 | AutoCAD Release 11, Release 12, AutoCAD LT 1 and LT 2 |
AC1006 | AutoCAD Release 10 | AutoCAD Release 10 |
AC1004 | AutoCAD Release 9 | AutoCAD Release 9 |
AC1003 | AutoCAD 2.6 | AutoCAD 2.6 |
AC1002 | AutoCAD 2.5 | AutoCAD 2.5 |
AC1001 | AutoCAD 2.4 | AutoCAD 2.4 |
How to open a DWG that's too new for your AutoCAD
- Ask the sender to use Save As and choose an older format, such as “AutoCAD 2013 Drawing”.
- Or convert it yourself with Autodesk's free DWG TrueView (DWG Convert) or the free ODA File Converter.
- If you only need to look at it, measure it or mark it up, open it in the free Caddis viewer, which reads Release 14 through AutoCAD 2018-format drawings (2007-format files only partially).
Frequently asked questions
How do I tell what version a DWG file is?
Every DWG starts with a six-character version code such as AC1032 or AC1027. Drop the file above and the checker reads that code and names the format, for example "AutoCAD 2018 format". You can also open the file in a text or hex editor and read its first six characters.
Why won't my AutoCAD open this DWG?
AutoCAD can't open DWG files saved in a newer format than its own. AutoCAD 2017, for example, can't open AutoCAD 2018-format files. Ask the sender to save down to an older version, or convert it with Autodesk's free DWG TrueView or the free ODA File Converter.
Is AutoCAD 2025 or 2026 a new DWG version?
No. AutoCAD 2018 introduced the current DWG format (AC1032), and later releases still save in it. That's why the checker reports "AutoCAD 2018 format" for files from newer releases.
Does the checker upload my drawing?
No. It reads the file inside your browser. The version is in the first bytes of the file, so the answer is instant even for large drawings.
What do AC1015, AC1018, AC1021, AC1024, AC1027 and AC1032 mean?
They are the version codes stored in DWG and DXF files: AC1015 is the AutoCAD 2000 format, AC1018 is 2004, AC1021 is 2007, AC1024 is 2010, AC1027 is 2013 and AC1032 is 2018. The table above lists every code.
Need to measure or mark up the drawing too?
The same engine powers the free Caddis viewer on the web and on iPhone. Open DWG, DXF, STEP and STL files, measure, and add markup, all on your device.
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