STL
.stl
3D models and geometry for 3D printing
Save as: STL / OBJ / PLY / OFF
SUPPORTED FILES
Files you can open and formats you can save.
The current free edition supports the following files. Files with the same extension may still fail to open because of their features or size.
OBJ
.obj
3D models. Select related files together to load materials and images.
Save as: STL / OBJ / PLY / OFF
PLY / OFF
.ply / .off
PLY meshes with faces and ASCII OFF. Geometry only.
Save as: STL / OBJ / PLY / OFF
3MF
.3mf
Models for 3D printing
Save as: GLB / glTF / STL / OBJ / PLY / OFF
glTF / GLB
.gltf / .glb
Supported 3D models with colors, materials and images
Save as: GLB / glTF / STL / OBJ / PLY / OFF
STEP / STP
.step / .stp
3D CAD exchange data
Save as: STL / OBJ / PLY / OFF
IGES / IGS
.iges / .igs
3D CAD exchange data
Save as: STL / OBJ / PLY / OFF
DXF
.dxf
Supported 2D CAD drawings
Save as: SVG
SVG
.svg
Supported vector shapes and text
Save as: PNG
Supported documents and drawings
Save as: current page in PNG
Adobe Illustrator
.ai
Only the viewable PDF content of AI files saved with PDF compatibility
Save as: current page in PNG
PNG / JPEG
.png / .jpg / .jpeg
Images
Save as: PNG / JPEG
AI files must be saved with Illustrator’s “Create PDF Compatible File” option. Editable layers and effects cannot be edited, and AI export is not supported. Non-PDF-compatible AI, EPS and PSD are currently unsupported.
OBJ .mtl files and images, and glTF .bin files and images, are companion files. They cannot be opened as standalone CAD models.
Free web edition
Open files and check their shape and size without CAD software. Use sections, measurements, color coding and supported format conversion with ease.
Pro (planned)
Planned to add larger-file support and convenient viewing, comparison and conversion features to the free edition. For anyone who needs larger or multiple datasets, with or without CAD software.
Pro is planned as an application installed on your computer.
FREE / PRO
Free / Pro comparison
Free features are available now; Pro entries describe planned features. Pro is not yet available, and its features, limits and pricing are not finalized. Both editions focus on viewing, checking, comparing and converting existing data, not creating new geometry or inferring 3D models from drawings.
On smaller screens, scroll the table horizontally.
Supported input files
| Feature | Free web edition | Pro (planned) |
|---|---|---|
| STL / OBJ / PLY / OFF | View supported meshes. Select OBJ materials and images together. PLY requires faces; OFF must be ASCII. PLY colors and normals are not retained. | Planned: include Free support and expand material and image handling. |
| 3MF / glTF / GLB | View supported static models. Partial support for colors, materials and images. | Planned: broader support for model structures, materials and images. |
| STEP / STP / IGES / IGS | View supported surface geometry. Original colors and part hierarchy are not retained. Display colors can be changed. | Planned: large CAD datasets, many parts and part hierarchies. |
| DXF | Lines, circles, arcs, straight polylines, points, single-line text, supported block geometry and stored dimension geometry. Geometry parallel to the XY plane is displayed in 2D without elevation. | Planned: more geometry, text and dimension types. |
| SVG | View supported static shapes and text. | Planned: broader viewing and shape conversion support. |
| View static pages, change pages and adjust quality. Quality is adjusted for large sheets. | Planned: multipage processing and reading drawing lines and dimension text. | |
| PNG / JPEG | View, pan and zoom images. | Planned: line extraction, correction and drawing recognition. |
| Illustrator（.ai） | View PDF-compatible AI only; save the current page as PNG. AI editing and export are unsupported. | Considering more formats once suitable reading methods are verified. AI editing and AI export are not planned. |
| Other CAD formats | DWG and vendor-specific formats are unsupported. | Considering additional formats that do not require individually negotiated agreements. DWG and vendor-specific support is undecided. |
Size and processing limits
| Feature | Free web edition | Pro (planned) |
|---|---|---|
| Size per file | STL/OBJ/PLY/OFF: 50 MiB. STEP/IGES/3MF/glTF/GLB: 16 MiB. PDF/AI/images/other: 8 MiB | Planned: larger datasets than Free. Size limit undecided. |
| Related files | 64 MiB total, up to 16 files | Planned: higher total size and file count. Limits undecided. |
| 3D complexity | Up to 1,000,000 triangles (STEP/IGES: 300,000) and 256 display groups. | Planned: many parts, dense geometry and lightweight viewing. Limits undecided. |
| STEP / IGES content | Up to 150,000 definitions / records. | Planned: large CAD processing using your PC’s memory. Limits undecided. |
| Image dimensions | Up to 4,096 pixels per side and approximately 16.77 million pixels in total. | Planned: higher-resolution images. Limits undecided. |
| PDF pages and quality | Up to 32 pages. One page at a time, with a maximum side length of 2,048 pixels. | Planned: more pages, higher-quality output and whole-document processing. Limits undecided. |
| DXF / SVG content | DXF: 20,000 entities. SVG: up to 1 MiB of document content and 20,000 shapes. | Planned: more entities and larger files. Limits undecided. |
| Processing time | Stops after 15 seconds normally, or 45 seconds when loading STEP / IGES. | Planned: longer large-data processing, progress displays and cancellation. Limits undecided. |
Conversion and export
| Feature | Free web edition | Pro (planned) |
|---|---|---|
| Mesh format conversion | Convert between STL, OBJ, PLY and OFF. Geometry-only output. | Planned: more conversion options for geometry, materials and images. |
| 3MF / glTF / GLB conversion | Save as GLB, single-file glTF, STL, OBJ, PLY or OFF. Retained information depends on the output format. | Planned: more input and output formats, with more retained information. |
| STEP / IGES conversion | Save as STL, OBJ, PLY or OFF. Original design information is not retained. | Planned: broader CAD conversion. Support, including STEP / IGES export, is undecided. |
| DXF / SVG conversion | DXF → SVG、SVG → PNG | Planned: conversions that retain shapes and text, and DXF export. |
| PNG / JPEG conversion | PNG ↔ JPEG. JPEG uses a white background. | Planned: batch processing and high-resolution output. |
| PDF image export | Save the current page as PNG. | Planned: image export of all pages and batch saving. |
| PDF → DXF | Unsupported | Planned: extract vector lines from PDFs and convert them to DXF. |
| Images / scanned drawings → DXF | Unsupported | Planned: extract, correct and vectorize existing drawing lines for DXF conversion. Unspecified geometry will not be inferred or added. |
| Batch file conversion | Unsupported | Planned: batch conversion and saving. |
Features and availability
| Feature | Free web edition | Pro (planned) |
|---|---|---|
| Viewing controls | 3D rotation, pan and zoom; standard XYZ views; 2D pan and zoom; fit view. | Planned: Free controls plus lightweight viewing for large data and saved view settings. |
| 3D measurement and sections | Straight-line distance and X/Y/Z differences between two surface points; three-point angle at B; X/Y/Z sections with colored cut faces on closed geometry, preserving holes and cavities. Display distances in mm, cm, m or inches. Display elements can change color and opacity. | Planned: part hierarchy management and advanced geometry analysis. |
| Volume and estimated mass | Estimate volume and mass for closed meshes up to 100,000 triangles. Choose a material density or enter density/specific gravity; display g or kg. Some shapes cannot be analyzed. | Planned: materials and mass per part, and analysis of multiple materials. |
| File processing | Processed on your device. Files are not uploaded to a server. | Planned: processing primarily on your device. |
| Availability | Use in your web browser. No sign-in required. | Planned: an installed 64-bit application. |
| Offline use | No downloadable edition is available. | Planned: offline use in the installed edition. |
| Advertisement | Advertisements may be displayed. | Planned: no advertisements. |
| Price | Free | A subscription is being considered. Pricing and purchase terms are undecided. |
| Part / display element color and opacity | Set color and opacity per display element; hide or isolate elements; automatically color-code all elements. Display only. | Planned: part hierarchy, name search, saved display sets and exploded views. |
| Preview images | Copy or save the current view as PNG, including orientation, colors, sections and measurement points. Copying requires permission in a supported browser. | Planned: batch image export from multiple views or models. |
| Shading and lines | Shaded, shaded with edges, visible lines only, or visible and hidden lines (approximate dashed lines). Line modes support up to 30,000 triangles. | Considering support for larger models and precise projected views. |
| 3D PDF | Currently unsupported. Regular PDFs are shown as static pages only. Basic 3D viewing is being considered as an addition. | Considering larger embedded 3D data, structure support and extraction. Currently unsupported. |
| Overall dimensions | Overall X, Y and Z dimensions of the display geometry. Coordinate values are shown when units are unknown. | Planned: dimensions per part, lists and comparisons. |
| Compare two datasets | View a single dataset. | Planned: side-by-side synchronized views, overlays and highlighting of possible differences. |
| Save views and measurements | Check on screen. Saving view settings is unsupported. | Planned: save view settings, notes and measurement lists on your device. |
| Part information list | Show available file information. | Planned: CSV lists of readable part names, quantities, materials, volumes and other information. |
| Save displayed images | Copy or save 3D previews as PNG; save displayed 2D and PDF images. | Planned: batch saving of high-resolution images, transparent backgrounds and multiple views. |
Free edition support and limitations (details)
Formats the free edition can view and convert
Some files may not open even with a supported extension, depending on their geometry or features.
STL / OBJ / PLY / OFF
Output: STL / OBJ / PLY / OFF
View mesh geometry. Planar quads and polygons in OBJ, PLY and OFF are triangulated. Select OBJ materials and images together with the model. Export contains geometry only; colors, materials, images and unit metadata are not retained.
3MF / glTF / GLB
Output: GLB / glTF / STL / OBJ / PLY / OFF
Supports static 3D models. GLB and glTF output retain supported transforms, base colors, materials and images. STL, OBJ, PLY and OFF output contain geometry only. Animations, compressed models and 3MF manufacturing settings are unsupported.
DXF
Output: SVG
Displays lines, circles, arcs, straight polylines, single-line text, supported block geometry and stored dimension geometry. Arcs are approximated by line segments and text uses substitute fonts. Hatching, splines and multiline text are unsupported.
SVG
Output: PNG
Render supported static shapes and text as an image. SVGs containing external images, fonts or scripts cannot be opened.
PNG / JPEG
Output: PNG / JPEG
View images and convert formats. Transparent areas become white in JPEG. Camera metadata and original color-management information are not retained.
Output: current page as PNG
View supported static PDFs, switch pages and adjust quality. Quality is adjusted when opening large sheets. Password-protected PDFs and forms are unsupported.
STEP / STP / IGES / IGS
Output: STL / OBJ / PLY / OFF
View supported surface geometry and convert it to a triangle mesh. Colors, materials, part hierarchy and design information are not saved. Some part placement methods may prevent loading. STEP and IGES export are unsupported.
PLY supports ASCII and binary meshes with faces. OFF supports ASCII geometry. Point-cloud-only PLY, COFF and NOFF are unsupported. PLY colors, normals and other attributes are not retained. OBJ, PLY and OFF polygons support up to 256 vertices per face; nonplanar and self-intersecting polygons are rejected. PLY and STL output may introduce float32 rounding errors. These mesh outputs contain no unit metadata.
DWG, vendor-specific formats, PDF / image-to-DXF conversion and 3D reconstruction from drawings are outside this viewer’s scope.
Curved surfaces are approximated, and information may be lost depending on the format. Check converted dimensions, units and geometry in suitable CAD software before machining or manufacturing.
File limits and system guidance
- STL/OBJ/PLY/OFF: 50 MiB. STEP/IGES/3MF/glTF/GLB: 16 MiB. PDF/AI/images/other: 8 MiB. Related files: 64 MiB total, up to 16 files.
- 関連ファイルは合計64 MiB・16ファイルまで。
- 3Dは合計100万三角形（STEP・IGESは30万）・256表示グループ（形状のまとまり）まで。
- Images: up to 4,096 pixels per side and approximately 16.77 million pixels in total.
- DXF: up to 20,000 entities. SVG: up to 1 MiB of document content and 20,000 shapes.
- PDF: up to 32 pages. Displayed one page at a time with a maximum side length of 2,048 pixels.
- STEP/IGES: up to 150,000 definitions / records. Loading stops after 45 seconds; other processing stops after 15 seconds.
Processing load varies with part count, curved surfaces and images, even at the same file size. Some files within the limits may still fail to open.
STL/OBJ/PLY/OFF: up to 1,000,000 triangles; STEP/IGES: 300,000. Section fill supports 200,000 triangles, volume/mass analysis 100,000.
PC guidance
Use 64-bit Chrome or Edge and a GPU that supports 3D rendering. As a guideline, 16 GB or more RAM is recommended; use 32–64 GB RAM and a dedicated GPU for heavier files. This is guidance, not a guarantee that every PC or file will work.
We recommend viewing smaller files on smartphones.
Formats being considered
These are possible additions, not currently supported formats. Adoption depends on verifying implementation methods and license terms that do not require individually negotiated agreements.
- 3D / CAD: BREP (.brep), COLLADA (.dae), FBX (.fbx), 3DS (.3ds), IFC (.ifc), Rhino (.3dm) and others.
- Design: EPS (.eps), Photoshop (.psd), non-PDF-compatible Illustrator (.ai) and others.
- CAD exchange: Parasolid (.x_t / .x_b), ACIS (.sat / .sab), JT (.jt) and others.
Vendor-specific CAD not currently supported directly
- SOLIDWORKS：.sldprt / .sldasm
- Autodesk Inventor：.ipt / .iam
- CATIA：.CATPart / .CATProduct
- Creo：.prt / .asm
- Siemens NX：.prt
Vendor-specific files cannot currently be opened directly. We do not plan to use reader SDKs that require individually negotiated agreements. Files exported from the original CAD software as STEP, IGES, STL or other supported formats can be opened within that format’s supported scope.
Getting started and format guides
Learn how to open 3D files and drawings, and check conversions and limits by format.