What is the NWD file format?
Files with the .nwd extension are generated by Autodesk Navisworks, software used for browsing and analysing architectural and BIM projects across disciplines. They are CAD files that embed all project data - including 3D models, their surroundings, the current view, saved viewpoints, animations, comments, markups, and clash-detection results - in a single portable document.
Differences between .nwd and .nwf files
Both formats are used within the Navisworks suite, but they differ substantially. .nwf files contain only links to data held in external source CAD files and are therefore dependent on those sources remaining accessible. .nwd files, on the other hand, embed the actual geometry and data from all referenced source files, rendering them self-contained. In other words, .nwd files function as exact snapshots of the full project at the moment of publishing.
Browsing and publishing .nwd files
These tasks are handled by separate applications within the Navisworks suite. The free Autodesk Navisworks Freedom viewer can open and navigate .nwd files, while Navisworks Manage and Navisworks Simulate are used for publishing and coordination work.
During the publishing process, additional controls can be applied - a password, a predefined expiry date, or a read-only restriction.
- All CAD project data are consolidated in a single
.nwdfile, making it straightforward to share with stakeholders who do not hold source-file licences. .nwdfiles are used primarily to present coordinated models and to identify clashes occurring between disciplines or sub-projects.- Because geometry is compressed and baked in at publish time,
.nwdfiles are typically much smaller than their source.rvtor.nwccounterparts.
Security & safety
RISK: LOWNWD files are BIM/CAD review data and are safe to open in the official Autodesk viewers. The realistic concern is confidentiality: an NWD can embed an entire project's geometry, properties and review history, so treat shared files as sensitive project data. Download Navisworks Freedom only from Autodesk's official site to avoid bundled-installer mirrors. An NWD can also be password-protected and given an expiry date by the publisher.
Format details
in a nutshellPrograms that open NWD files
Windows2 apps
Autodesk Navisworks Freedom
Free Install the free Navisworks Freedom viewer, then open the .nwd to navigate, section, measure and read the model's viewpoints/markups.
Autodesk Navisworks Manage / Simulate
Paid Open the .nwd for full review, clash detection, 4D simulation and appending other models. Use only if you need more than viewing. Technical details
deep spec| Container architecture | Proprietary binary container with internal compression; no publicly documented constant magic-byte signature - identified by extension and Navisworks publishing origin |
| Data embedding model | All source geometry, materials, object properties, and metadata are baked in at publish time; the file requires no external references to open |
| Geometry representation | Source CAD geometry is tessellated into Navisworks internal faceted mesh at publish time; exact NURBS or parametric data is not preserved |
| Compression | Internal data is compressed, producing files substantially smaller than the original source `.rvt`, `.dwg`, or `.ifc` equivalents |
| Saved viewpoints | Camera positions, section cuts, and hidden-item states saved in Navisworks are embedded and playable in Navisworks Freedom |
| Clash Detective results | Can store clash detection results (hard, soft, and clearance clashes) with status, comments, and assigned responsibility from Navisworks Manage |
| TimeLiner (4D data) | Supports embedded TimeLiner schedule data linking model objects to construction tasks for 4D simulation playback |
| Markups and comments | Redline markups, tags, and text comments authored in Navisworks tools are preserved in the published `.nwd` file |
| BIM object properties | Preserves property sets inherited from source files, including Revit instance parameters, IFC attributes, and AutoCAD object data |
| Publishing controls | Password protection, read-only mode, and a time-limited expiry date can be applied when publishing from Navisworks Manage or Simulate |
| Coordinate alignment | Maintains shared global coordinates, enabling multi-discipline models from different authoring tools to remain federated and aligned |
| Platform support | Windows only; Autodesk has not released a macOS or Linux version of any Navisworks application |
| MIME type | application/octet-stream - no dedicated registered MIME type exists for `.nwd` |
| Difference from `.nwf` | Unlike `.nwf` (which stores only links to external source files), `.nwd` embeds all data, making it suitable for sharing outside the project team without access to authoring tools |
| Released | 2007 (Autodesk acquired NavisWorks; earlier as JetStream NWD) |
| Specification | www.autodesk.com |
NWD conversions
Community Q&A
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