A better way through file formats

Convert and Repair 3D Files Online

Convert STEP, STP, STL, OBJ, GLB/GLTF and 3MF files, and repair STL meshes, online. Inspect a free 3D preview first, then pay once per file only if you want the full-quality download.

Convert STEP to STL Explore all tools

No account needed

Unpaid files deleted within 60 min*

Preview before you pay

One-time payment, no subscription

The toolkit

The right tool for the file in front of you.

Pick a conversion, check a model, or prepare a mesh for printing. Pricing is per file, and browser-only tools are free.

STEP to STL

Turn CAD solids into a mesh for slicing and printing.

$3.99 / file

STP to STL

Convert an .stp file with the same STEP geometry workflow.

$3.99 / file

STL to STEP

Create a faceted STEP solid from a triangle mesh.

$5.99 / file

STL Repair

Find mesh problems and inspect what repair improved.

$4.99 / file

STL Fixer

Check and improve common mesh issues before downloading.

$4.99 / file

STL to OBJ

Move an STL mesh into an OBJ-based workflow.

$2.99 / file

OBJ to STL

Make an OBJ mesh ready for STL-based tools.

$2.99 / file

GLB/GLTF to STL

Convert self-contained glTF mesh geometry to STL.

$2.99 / file

3MF to STL

Convert placed 3MF mesh objects to STL in millimetres.

$3.99 / file

STL to 3MF

Package STL geometry as a single millimetre-based 3MF object.

$3.99 / file

3MF Viewer

View a local 3MF and its declared units in your browser.

Free

STL Viewer

Inspect STL or OBJ geometry directly in your browser.

Free

STL File Viewer

Open and inspect STL files in your browser.

Free

Online STL Viewer

View STL files online without uploading your model.

Free

STL Model Viewer

Rotate and examine an STL model in your browser.

Free

STEP Viewer

Open a STEP file as an interactive low-res preview.

Free

STL Editor

Scale, rotate, mirror and export STL locally.

Free

File guides

Find the right next step.

Short guides for viewing, editing and understanding common 3D file formats.

How to open an STL file

Choose a viewer or tool for your model.

Read guide →

How to edit STL files

Know when to edit a mesh or return to CAD.

Read guide →

What is an STP file?

Understand this common STEP exchange format.

Read guide →

What is an SLDPRT file?

Learn what a native SolidWorks part contains.

Read guide →

What is a 3MF file?

Understand 3MF units, assemblies and appearance metadata.

Read guide →

How it works

See the result first. Decide after.

No checkout to cross before you know whether a conversion is useful.

01 / UPLOAD

Choose your file

Upload limits are per tool: STEP/STP to STL 50 MiB; STL to STEP 50 MiB; STL Repair 50 MiB; STL to OBJ 50 MiB; OBJ to STL 50 MiB; GLB/GLTF to STL 50 MiB; 3MF to STL 50 MiB; STL to 3MF 50 MiB; STEP Viewer 50 MiB. Browser-only viewers and STL Editor accept up to 100MB. Complex models may still exceed processing limits; you are not charged if verification fails.

02 / PREVIEW IN 3D

Look closely

Orbit, zoom and inspect a lower-resolution preview. For repairs, compare the mesh before and after.

03 / DOWNLOAD

Pay only if you like it

If the result is right, make a one-time payment to download the full-quality file. No account or subscription.

Straightforward pricing

One file. One price.

Preview is free. You pay for a full-quality download, not for trying a tool.

Tool	What you get	Price / file
STEP to STL / STP to STL	Full-resolution STL mesh	$3.99
STL to STEP	Faceted STEP geometry	$5.99
STL Repair / STL Fixer	Repaired STL mesh	$4.99
STL to OBJ / OBJ to STL	Converted mesh file	$2.99
GLB/GLTF to STL	Converted mesh file	$2.99
3MF to STL / STL to 3MF	Converted mesh file	$3.99
3MF Viewer / STL Viewer / STEP Viewer / STL Editor	View or edit your file	Free

*Unpaid files without checkout are deleted within 60 minutes. Jobs with checkout started are kept for at least six hours; Paddle-confirmed completed payments are protected from unpaid cleanup. Paid files are retained for up to 7 days so you can re-download, unless deleted sooner.

Frequently asked questions

Do I have to pay to preview a conversion?

No. The interactive low-resolution preview is available before checkout. Payment is only required to download the full-quality output.

Do I need an account or subscription?

No. StlFixTool charges per file for a full-quality download and does not require an account or subscription.

How long are uploaded files kept?

Unpaid jobs with no checkout and their files are deleted within 60 minutes. Jobs with checkout started are kept for at least six hours, and Paddle-confirmed completed payments are not removed by unpaid cleanup. Paid jobs are retained for up to 7 days for re-download, unless you delete them sooner.

Does STL to STEP recreate editable CAD features?

No. It creates a faceted representation of the input triangles. It does not infer the original sketches, dimensions, or parametric feature history.

What is the maximum upload size?

Upload limits vary by tool and are shown beside each file picker. Browser-only STL Viewer and STL Editor accept files up to 100 MiB (104,857,600 bytes).

Which tools keep my file on my device?

STL Viewer (STL and OBJ files), 3MF Viewer and STL Editor run in your browser without uploading your file. STEP Viewer, conversions and STL repair require server processing.

Ready when you are

Bring the file. We'll help with the format.

Start with a free preview, then decide what to do next.

Start converting