.dwg

What is a .dwg file?

DWG is AutoCAD's native file format — the de facto standard for 2D and 3D engineering drawings in architecture, construction, and mechanical design.

Safe format
Type Cad
By Autodesk
MIME application/dwg

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What is it

You received a DWG file from an architect, an engineer, or a construction firm. Every blueprint, floor plan, and site layout in a modern building project passes through DWG at some point. The format is Autodesk AutoCAD's native file, and its dominance in the CAD world is so complete that competing software must support it to remain relevant.

DWG is a proprietary binary format — Autodesk controls the specification, though the Open Design Alliance has reverse-engineered it to provide independent read/write support. The format stores 2D drawings and 3D models with layers, dimensions, annotations, blocks, and external references (xrefs). Files from different AutoCAD versions use different DWG versions, which occasionally causes compatibility headaches when old and new software meet.

AutoCAD (subscription, expensive) is the definitive editor. DWG TrueView (free, Autodesk) opens and converts DWG files but can't edit. LibreCAD (free, open-source) handles simpler 2D DWG files. Autodesk Viewer (free, web-based) lets you view DWG in a browser. For exchanging CAD data between different software, DXF is the more portable interchange format.

Technical details
Full Name
AutoCAD Drawing
MIME Type
application/dwg
Developer
Autodesk
Magic Bytes
41 43 31 30
Safety
.dwg is a known, safe format.
What opens it
AutoCAD
Subscription Windows
DWG TrueView
FREE Windows
LibreCAD
FREE All
Autodesk Viewer
FREE Web

* Limited DWG support

FAQ
How do I view a DWG file for free?
Autodesk offers DWG TrueView (Windows, free) and Autodesk Viewer (web, free) for viewing DWG files without a full AutoCAD licence. LibreCAD (free, all platforms) can also open DWG files with limited support.
What's the difference between DWG and DXF?
DWG is AutoCAD's native binary format — compact and full-featured. DXF is an exchange format designed for interoperability between CAD programs. If you need to share drawings with someone using different software, export as DXF.
How do I convert a DWG file?
AutoCAD can export to DXF, PDF, and other formats. For free conversion, Autodesk's online viewer can export to PDF. ODA File Converter (free) converts between DWG versions and to DXF.
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