Is it free to convert between STL and OBJ?

Yes, Convert999 is 100% free. All conversions happen locally in your browser with no file size limits, no registration, and no watermarks.

.stl

.obj

STL vs OBJ

Compare Stereolithography and Wavefront OBJ formats — understand the key differences and when to use each

Format Overview

STL

Stereolithography

Stereolithography (.stl) is a 3d file format.

.stl3d

OBJ

Wavefront OBJ

Wavefront OBJ (.obj) is a 3d file format.

.obj3d

STL vs OBJ: Feature Comparison

Feature	STL	OBJ
Full Name	Stereolithography	Wavefront OBJ
File Extension	.stl	.obj
Category	3d	3d
Free to Convert	✓ Yes	✓ Yes
Browser Support	✓ All Browsers	✓ All Browsers
Convert to Each Other	✓ Yes	✓ Yes

When to Use STL vs OBJ

Use STL when you need:

•Files in Stereolithography format for maximum compatibility
•Industry-standard 3d format support
•Wide software and platform compatibility

Use OBJ when you need:

•Files in Wavefront OBJ format for specific workflows
•Optimized 3d format features
•Modern format advantages and smaller file sizes

Convert Between Them

STL OBJ OBJ STL

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Frequently Asked Questions

What is the difference between STL and OBJ?

STL (Stereolithography) and OBJ (Wavefront OBJ) are both 3d file formats. STL files use the .stl extension while OBJ uses .obj. They differ in compression, quality, compatibility, and intended use cases.

Can I convert STL to OBJ for free?

Yes! Convert999 lets you convert STL to OBJ completely free, directly in your browser. No file upload to any server, no registration needed — your files stay private on your device.

Which is better, STL or OBJ?

It depends on your use case. STL (Stereolithography) may be better for certain workflows, while OBJ (Wavefront OBJ) excels in others. Consider factors like file size, quality, software compatibility, and your specific needs.

Is it safe to convert files on Convert999?

Absolutely. Convert999 processes all files 100% locally in your browser. Your files are never uploaded to any server, ensuring complete privacy and security.

STL Converter

Convert from STL

OBJ Converter

Convert from OBJ

File Tools

Compress, resize, merge

Convert to STL

All sources → STL

Convert to OBJ

All sources → OBJ

Format Statistics

Trends & data 2025

More Format Comparisons

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Feature

STL

OBJ

Full Name