OpenCAD offers a free online CAD editor and file viewers with no installation or sign-up. Open, draw, edit and save DWG and DXF drawings in your browser. Use dedicated viewers for STEP/STP 3D models, SketchUp SKP files and NC, G-code or MPR toolpaths. Files stay in your device’s browser instead of being uploaded to a server.
What is browser CAD, and what does OpenCAD offer for free?
Browser CAD runs in a web browser instead of requiring a desktop installation. OpenCAD is Sean Kim’s open-source project offering free CAD editing and file viewers. Choose the DWG/DXF editor or a STEP, STP, SKP or NC viewer on this page to get started.
Can I edit both 2D drawings and 3D models?
The DWG/DXF editor supports opening, creating, editing and saving 2D drawings. The STEP/STP and SketchUp SKP tools are viewers for inspection and measurement; they do not provide the original CAD application’s full modeling features. Check the guide for your file format before choosing a tool.
Is it free, and where are my drawings processed?
All four published tools are free to use without installation or sign-up, and their source code is available under the MIT license. Drawings and models are processed in your device’s browser. Each tool links to its source code and supported features.
How does OpenCAD differ from FreeCAD?
FreeCAD is a separate project for creating parametric 3D models with a design history. OpenCAD edits DWG/DXF drawings and views STEP, SKP and NC files in the browser. It does not open FreeCAD's native .FCStd files; export a model from FreeCAD as STEP to inspect its 3D geometry here. FreeCAD features and supported formats
Are OpenCAD and OpenSCAD the same program?
They are separate projects. OpenCAD on this site provides a DWG/DXF 2D online CAD editor and STEP, SKP and NC viewers. It is separate from OpenSCAD, which creates 3D models from scripts. These OpenCAD tools do not edit .scad files. About OpenSCAD on its official site
A free online CAD editor for opening, drawing, editing and saving DWG and DXF files without installation or sign-up. Measure distances, angles and areas, and export PDF, PNG or SVG.
Open
DWG R13–R2018, DXF R12–R2018 files and new blank drawings
Confirm
Distance including height (Z) and cumulative distance across several points, angle, area and mass properties (MASSPROP) measurement; layers, dimension list, text search
Edit
Drawing and modify commands, right-button drag to move or copy, Tab to cycle through overlapping snaps, tangent snaps that also work on ellipses and splines, dimensions, hatches, blocks, purging unused items (PURGE)
Save
Save as DWG or DXF, with a notice before saving about objects the target format would drop
Output
PDF, PNG and SVG output, several layouts in one PDF (PUBLISH), layers you can toggle and text you can search inside the PDF
Mobile
A view mode instead of the editing ribbon: measure distance, radius, angle and area, choose object snaps, find point coordinates and text, and see dimensions of the object you tap. Added to the home screen, it opens without an internet connection
This is a free viewer that opens STEP·STP 3D CAD files in the browser without installation. You can check the assembly structure and part properties, measure hole diameters and distances between faces, and look inside with section and exploded views.
Format
B-rep geometry, assemblies, colors, units and PMI annotations from STEP AP203, AP214 and AP242
Navigation
Select several parts, bodies or faces together, then hide, isolate, fade the rest and view part properties from the product tree or the right-click menu
View
Standard views, shaded and wireframe, hidden line removal, X-ray, sections, exploded view that separates the assembly level by level
Measure
Point-to-point distance that snaps to circle centers, midpoints, intersections and perpendicular feet, with Shift direction lock; edge length and hole diameter; distance and angle between faces; volume and mass; moments of inertia; interference check that also finds parts enclosed inside others
Export
Large PNG and transparent-background images, STL and OBJ files, the measurement log as CSV, and a view link that captures the current view
Mobile
A single row of view and measure buttons, plus a measure bar and press-and-hold precise aiming to check distances and face dimensions. Several parts can be selected together by touch as well. Added to the home screen, it opens without an internet connection
This is a free viewer that opens SKP files saved in SketchUp 6-2026 in your browser. You can look through tags, materials, groups and components, tour the space with scene playback and walk mode, and measure distances and angles.
Format
.skp files saved from SketchUp 6, 7, 8 and 2013-2026. Files from SketchUp 5 or earlier cannot be opened yet.
Navigation
Turn tags on and off, check materials, find groups and components by name, pick a single face or edge to see its area or length
View
Opens with the file's style, down to the background and edge colors (including edges colored by material), seven display modes, shadows and fog, multiple section planes with section fill
Scenes
Scene tabs and scene playback, walking that stops at walls and follows the floor, field-of-view control, two-point perspective
Measure
Tape measure and protractor that snap to endpoints, midpoints, circle centers, perpendicular feet and intersections, with Shift direction lock; place and undo guide points and guide lines (kept when you reopen the same file); copy the last 10 measurements; save and print images
Mobile
A single row of view and measure buttons, press-and-hold precise aiming for the tape measure and protractor, and a joystick for walking. Added to the home screen, it opens without an internet connection
A free NC viewer for checking 3D toolpaths in G-code, Heidenhain (Klartext and DIN/ISO) and panel machining files (woodWOP MPR, WangShi PGI, KDT XML). You can trace code lines together with their moves and replay the machining sequence while watching the stock being cut. Lines to check before the program goes to the machine are flagged as warnings.
Format
G-code in the ISO, Fanuc, Haas, Siemens, LinuxCNC, GRBL and Mach3 families, Heidenhain Klartext and DIN/ISO, woodWOP MPR, WangShi PGI, KDT XML
Path/Route
3D toolpaths linked to code lines, per-tool display, machining sequence playback, stepping one move at a time, code search, 3-axis simulation that cuts the stock up to the replayed position
Information
Feed and rapid move lengths, estimated time, cutting extent and deepest Z, feed, spindle and offset state of the selected line, operations and variables in panel machining files
Warnings
Warns about lines such as H or D numbers that differ from the tool number, cutting with the spindle stopped, or rapids below the deepest cut, and jumps to the line when tapped
View
Rotate and zoom, standard views, sections, two-point measurement that snaps to arc centers, midpoints, intersections and perpendicular feet, Shift direction lock (tangent direction on arcs and splines), PNG export
Mobile
A single row of view, measure and playback buttons, plus a measure bar and press-and-hold precise aiming to check the distance between two points on the toolpath. Added to the home screen, it opens without an internet connection
This is a WebGL2-based 3D viewer library used by NC, STEP, and SKP viewers. It provides common functions to receive, display, select, and measure scenes created by an interpreter.
Use free browser-based OpenCAD on Mac or Windows to open DWG/DXF files, create drawings, edit and save them. Check supported versions, layers, fonts and PDF output.
Open STEP and STP 3D files without installation. Use free OpenCAD to inspect assemblies, saved PMI, distances and sections, and troubleshoot blank views or missing geometry.
View SKP files online for free without installing SketchUp. Explore options after the desktop viewer download ended, supported versions, tags, scenes and measurements.
Inspect toolpaths from G-code, Heidenhain and panel machining files (MPR, PGI, XML) with the free OpenCAD NC viewer. Follow code lines during playback and check dialects, units and parser warnings.
Choose a free viewer for the CAD file you received. Compare DWG and DXF, STEP and STP, and SketchUp SKP; learn how to open them on Windows or Mac and prepare a design-to-factory handoff.
