OST Visualizer

Open your On-Screen Takeoff projects and review them in 2D plan view. Upgrade to visualize in 3D, edit conditions, and export to DXF, PDF, and OBJ.

Source-available under Elastic License 2.0

Download Free Get Commercial License

Latest: v1.2.2.3 · Windows

Features

Everything you need for 3D takeoff review

Built for construction estimators who work with On-Screen Takeoff daily.

2D Plan View

Interactive view with annotations overlaid on project pages.

PDF

PDF Plan Sheets

View PDF drawings at any scale.

Multi-Database

Open and browse multiple project files at the same time.

BID

Bid Organization

Full project hierarchy for navigating bids and conditions.

3D VisualizationCommercial

See takeoff geometry rendered in full 3D with transparent overlays.

I/O

Import / ExportCommercial

Move data between OST, OSP, PDF, DXF, OBJ, and FBX formats.

Condition ManagementCommercial

Create, edit, duplicate, and organize conditions across bids.

Realtime Sync (free companion tool)

Detects when On-Screen Takeoff is active and picks up changes automatically.

Licensing

Free vs. Commercial License

OST Visualizer is source-available under the Elastic License 2.0. A commercial license unlocks all features for production use.

	Free (Viewer)	Commercial License
Open and browse projects	✓	✓
2D plan view (read-only)	✓	✓
3D visualization	—	✓
Edit takeoffs, conditions, bids	—	✓
Import/Export (PDF, DXF, OBJ, FBX)	—	✓
Production use	—	✓
Support	Community	Email (fabian@fabianhad.com)
Price	Free	Get a license

License Terms

Elastic License 2.0

OST Visualizer is source-available. Here's what the license allows.

What you can do

View source code — read, study, and learn from the codebase
Contribute — submit pull requests and improvements
Non-production use — run the software for development, testing, and personal evaluation
Production use with a license — use all features in commercial environments with a valid license key

What you cannot do

Circumvent the license key — you may not disable, remove, or bypass license key functionality
Offer as a hosted service — you may not provide the software to third parties as a managed service
Remove notices — you may not alter or remove licensing or copyright notices

Who it's for

Built for construction professionals

Estimators

Reviewing On-Screen Takeoff projects visually before bidding.

Project Managers

Inspecting bid scope across multiple databases.

Construction Teams

Working with takeoff data in 2D and 3D.

Technology

Built for performance

Native desktop application with hardware-accelerated 3D rendering.

Python C++ PySide6 OpenGL nanobind

Performance-critical rendering in C++ with nanobind Python bindings. Qt-based UI. View on GitHub for full details.