STEP to STL File Converter: Free & Online

Convert single parts or full assemblies from .STEP to .STL (Stereolithography) file format and prepare 3D models for printing in one app.

Trusted by 10,000+ engineers
No limits
Automatic Mesh Repair
SSL & Auto-Delete
Video coming soon

Read our step-by-step guide:

Which STEP to STL Converter Is Best for You?

Compare STEP to STL converters and find the best fit for your workflow

MeshInspector App
MeshInspector Web
Other Converters
Speed
Ultra-fast Local processing
Fast
Slow
File Size Limits
Unlimited
Unlimited
File size limit (50 MB)
File Number Limits
Unlimited
Unlimited
Usually single file only
Folder Support
Full folder import
Full folder import
Not supported
Assembly Conversion
Partial or full assembly
Partial or full assembly
Not supported
Mesh Validation
Integrated
Integrated
Not supported
Auto Mesh Repair
Advanced
Advanced
Not supported
Mesh Repair Options
Advanced
Advanced
Not supported
Accuracy Control
Full
Full
Not supported
3D Viewer
Advanced
Advanced
Basic or no preview
3D Editor
Advanced
Advanced
Not supported
Security & Privacy
100% Local No upload needed
SSL + Auto-delete
Files often stored on servers
Cross-Platform
Windows, macOS, Linux
All devices
Web only, limited mobile UX
Suitable for
Professionals and engineers
Quick online conversions
Not recommended

Ready to Convert Your STEP Files?

Join thousands of engineers who trust MeshInspector for their 3D file conversion needs. Start converting today with no limits and professional results.

How to Convert STEP to STL in MeshInspector Software

1

Opening STEP Files

Click ‘Open Files’ in the top toolbar under the ‘Home’ section.

2

Browsing STEP Files

In the dialog window that appears, navigate to your .step or .stp file, select it, 
and upload it.

3

Viewing STEP Files

Once loaded, your model will appear in the workspace as a triangular mesh ready for preview and further STEP to STL conversion.

4

Exporting Components

We handle large assemblies with no file size limits, letting one export individual parts or entire models. In ‘Scene Tree,’ click the part, then select ‘Export’.

5

Export as a Single Model

To export an entire assembly as one mesh, upload your STEP file and combine its parts. In ‘Scene Tree’, select the desired group, right-click, and choose ‘Combine Subtree’ to merge components. Then repeat the ‘Export’ action from previous steps.

6

Setting the STL format

In the dialog window, choose STL under ‘Extension.’ The program saves it in Binary STL format. Click ‘Save’ to complete the STEP to STL conversion.

7

Inspecting the Size

After conversion, use MeshInspector to check your model’s dimensions. Go to ‘Inspect’ and open ‘Bounding Box’ to verify that the mesh fits your printer.

8

Adjusting the Size

If the scale needs adjustment, use the ‘Transform’ in the lower left and drag the scaling bar. This will ensure your STEP to STL conversion results in a correctly sized and print-ready model. Do not forget to save the results.

9

Finding ‘Mesh Repair’

If the scale needs adjustment, use the ‘Transform’ in the lower left and drag the scaling bar. This will ensure your STEP to STL conversion results in a correctly sized and print-ready model. Do not forget to save the results.

10

Verifying the Quality and Fixing the Object

The ‘Mesh Healer’ tool can detect and fix disconnected parts, holes, self-intersections, flipped normals, zero-area triangles, as well as small tunnels. On top of that, you can employ ’Thin Walls’ and ’Undercuts’ checks to confirm printability before exporting. This step secures top-quality results from your STEP to STL conversion.

User Testimonials

4.9/5
out of 5 based on 2,547 reviews

Gabriele Impellizzeri

R&D Manager

MeshInspector significantly helped us in streamlining all of our 3D printing mesh modeling tasks thanks to its ability to fix, smoothly decimate and operate on our large-size lattice meshes in a fast and effective way.

Erick Geisler

Chief Technical Officer

"MeshInspector has completely transformed our workflow. It\'s faster, more efficient, and offers incredible value. The responsiveness of the development team and the quality of the software have given us a significant edge over our competitors."

Peter Sekula

Chief of Operations | Matterfield

"MeshInspector proves invaluable for 3D artists with its swift decimation and powerful Python API, streamlining workflows and enhancing efficiency. Its automation capabilities render it indispensable in the realms of gaming and VFX."

Daniel Gelep

3D Scanning Representative, Susteni AS

"It's the fastest program I\'ve used so far, and I can now do 150 scans in just 2 days instead of 1.5 weeks."

Ruedger Rubbert

Chief Technology Officer, Brius Technologies Inc

"With MeshInspector MeshLib we were able to automate many of our workflow processes, thanks to its advanced, modern, and efficient dental and geometry oriented algorithms, covering many of our orthodontic-related tasks: CT and intraoral scan segmentation, voxel and Boolean operations, editing, aligning, visualization, inspection, and import/export of mesh objects. We use the versatile MeshInspector MeshLib API, both in production and R&D for fast prototyping and testing of our ideas."

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