What is the EASM file format?
The .easm file extension is used for files containing 2D/3D assembly drawings created with CAD software and published via the eDrawings Publisher plugin - built into SolidWorks or available as an add-in for other CAD packages. An .easm file is a read-only representation of a CAD assembly, not the actual project design. It packages together the related parts of a .sldasm assembly into a compact, proprietary compressed binary container.
A project saved as an .easm file can be viewed, measured, and printed, but not edited. The originating designer therefore has a guarantee that recipients of the file will not be able to access or modify restricted project data. Because .easm files are small in size, they are well suited for CAD assembly distribution over the web or by email without exposing native source files.
- eDrawings files are rendered using the HOOPS Visualize graphics engine, developed by Tech Soft 3D (formerly TechSoft America).
- The
.easmformat is closely related to.edrw(eDrawings Drawing) and.eprt(eDrawings Part) - all three are read-only eDrawings publication formats produced from their respective SolidWorks source types. - Free viewing is available through eDrawings Viewer on Windows, macOS, iOS, and Android.
Security & safety
RISK: LOWEASM files are CAD viewing data and are generally safe to open in eDrawings Viewer. The realistic concern is confidentiality, not malware: an assembly may reveal proprietary product design, so treat shared .easm files as sensitive. Only download the viewer from the official eDrawings/SOLIDWORKS site to avoid bundled-installer sites.
Format details
in a nutshellPrograms that open EASM files
Windows2 apps
SolidWorks
Paid Open eDrawings files; if the original .sldasm is available, edit there instead. eDrawings Viewer is enough just to view. 
eDrawings Viewer
Free Install the free eDrawings Viewer, then double-click the .easm to rotate, zoom, explode and measure the assembly. 
macOS1 app
eDrawings Viewer for Mac
Free Download the macOS build of eDrawings, then open the .easm to view and review the assembly. 
Android1 app
eDrawings (Android app)
Free Open the .easm in the eDrawings Android app to view and rotate the assembly.
eDrawings (iOS app)
Free Open the .easm from Files/email in the eDrawings app to view the 3D assembly on iPhone/iPad. Technical details
deep spec| Developer | Dassault Systèmes (SolidWorks) |
| File type | Read-only CAD assembly publication |
| Container format | Proprietary compressed binary |
| MIME type | application/octet-stream |
| Source format | SolidWorks Assembly (`.sldasm`) |
| Rendering engine | HOOPS Visualize (Tech Soft 3D) |
| Editable | No - view-only; content cannot be modified by recipients |
| Supported operations | View, rotate, measure, cross-section, print, markup |
| Related formats | `.eprt` (eDrawings Part), `.edrw` (eDrawings Drawing) |
| Platform support | Windows, macOS, iOS, Android |
| Free viewer | eDrawings Viewer (available on all supported platforms) |
| Export source | SolidWorks via Save As, or eDrawings Publisher add-in for AutoCAD and other CAD tools |
| Assembly content | Geometry of all component parts, assembly structure, and embedded metadata |
| Magic bytes | No publicly documented fixed signature; identified by extension and export origin |
| Released | 2000 (eDrawings, SolidWorks Corporation) |
| Specification | www.edrawingsviewer.com |
EASM conversions
Community Q&A
asked by usersNo questions yet - be the first to ask about EASM files.
