01
FORMAT TO FORMAT
Convert STEP to STL and 60+ similar routes.
Move between CAD solids, surfaces, meshes and drawing formats without installing another application.
STEPSTLSTLSTEPIGESSTEP
YOUR #1 CAD CONVERSION WORKSPACE
The CAD converter experts.
Change the format or turn a 3D model into a 2D drawing set. Marathon OS gives you 60+ specialist tools, precise outputs and the fastest path from the file you have to the file you need.
No software installUp to 300 MBAuto-delete in 7 days
MARATHON CONVERSION DESKChoose the result you need
ONLINESOURCE FILEAuto-detectfrom uploaded file
CONVERT
WHY THIS ROUTEConvert STEP to STL for 3D printing and slicing.
Drag and drop your 3D file here
or choose a file from your computer
Browse filesMaximum file size: 300 MB
Files under 5 MB convert and download free. For larger files, 1 credit = one download of any size — buy a pack.
Don't have a file? Try a sample:
150,000+files converted
10 TB+CAD data handled
60+specialist conversion tools
300 MBsupported per file
TWO CONVERSION JOBS. ONE SPECIALIST PLATFORM.
Tell us what the next step needs.
Choose a new file format for the same geometry, or create a clear 2D drawing set from a 3D model.
02
3D CAD TO 2D
Turn STEP or STP into a usable drawing set.
Create multi-view technical sheets for quoting, review, documentation and workshop handoffs.
PDFSVGDXFPNG
CONVERSION FIRST, BY DESIGN
Not a toolbox with a converter hidden inside.
Marathon OS is built around the handoff between file formats. We help engineers, makers and production teams get from the file they received to the file the next tool can use.
60+ DIRECT TOOLS
Our fastest path to the right format
Go straight to the exact source and target pair. No software install, no plugins and no long setup before the real work can continue.
10 ENGINEERING FORMATS
Our most precise conversion workflow
See the input, output and intended use before you start. We also explain when moving between CAD and mesh formats can change editability.
VIEW BEFORE YOU MOVE ON
A result you can inspect
Open supported files in the Marathon OS viewer before or after conversion, so the output is not a blind download.
SPECIALIST CONVERTERS
Every common CAD handoff, in one place.
Start with the exact route your next application, printer, supplier or production workflow requires.
STEPSTLMOST USED
Prepare CAD geometry for slicing and 3D printing.
Open converterSTLSTEP
Move mesh geometry into a CAD-compatible workflow.
Open converterIGESSTEP
Bring legacy surfaces into a modern CAD handoff.
Open converterSTEPIGES
Exchange engineering geometry across older CAD systems.
Open converterOBJSTL
Create a practical mesh file for printing workflows.
Open converterOBJSTEP
Take mesh geometry into a mechanical CAD workflow.
Open converterDWGDXF
Make 2D drawings easier to exchange across tools.
Open converterDXFDWG
Move exchange drawings back into a DWG workflow.
Open converterFORMAT EXPERTISE
CAD solids are not meshes. Drawings are different again.
The best conversion starts with understanding what the file contains and what the next workflow expects. Marathon OS makes that distinction clear before you upload.
Clear quality notes explain when a format change may affect features, surfaces or editability.
Explore supported formats01
CAD solids and surfaces
For mechanical CAD, supplier handoffs and manufacturing workflows.
STEPIGESBREP3DM
02
Meshes and 3D printing
For slicing, printing, scanning, rendering and mesh editing.
STLOBJPLYOFF
03
2D technical drawings
For drafting exchange, production drawings and downstream tools.
DWGDXF
BUILT TO KEEP WORK MOVING
From incompatible to ready in three clear steps.
Start from the converter that matches your exact task. Upload only when you reach that dedicated route.
Choose the route
Select the format you have and the format the next workflow needs.
Convert securely
Upload on the dedicated converter page and process the file in your browser workflow.
Inspect and continue
Download the result, preview supported geometry and move the job forward.
MARATHON OS CAD VIEWER
See the file before and after conversion.
Inspect supported CAD and mesh files in your browser without installing another application.
PRIVATE FILE HANDLING
Your engineering files stay your files.
Encrypted during uploadProcessed privatelyDeleted after 7 daysNever added to the public library
3D CAD PRODUCTS
Start from a model that is ready to work.
Browse 10,000+ quality-checked 3D CAD products for design, prototyping and manufacturing.
3D Printing
Pico-Ice Rev3 | 3D Engineering Design File
3D Printing
Rodholder 1 | 3D CAD Engineering Model
3D Printing
Edge Lamp 1 | 3D CAD Engineering Model
3D Printing
Cairo30 Open-Source 3D Printer - High-Speed, Rigid CNC Machine
2D CAD PRODUCTS
Put a clear drawing in front of the workshop.
Explore 3,096 technical drawing sets with practical outputs for quoting, review and production.
PDF · SVG · DXFDrawing set
1st angle projection
BIO REACTOR, Used for CFD Analysis for Projects
PDF · SVG · DXFDrawing set
1st angle projection
M12 X-CODE CAT6A Plug - High-Performance Industrial Connector
PDF · SVG · DXFDrawing set
1st angle projection
M12 X-Code Connector - High-Performance Industrial Connector
MARATHON OS CAD CONVERSION
The file you need is one conversion away.
Change the format or create the drawing set. Choose the exact result and keep the project moving.
15,000+ files converted across 60+ specialist toolsRecently added / Trending
Everything you need to design faster, smarter, and with more impact.
Waste Cart 2 | Professional CAD Design
Citizen Watch 3D Model - Detailed Timepiece Design
Solidworks 3D Design And Assembly Of A Collaborative Surgery Robot - Downloadable CAD Representation
Draga Estandar - Standard Mechanical Component
Automotive and Mechanical Engineering Component
45 Deg 6Mm Gease Nipple 12Mm Socket 1 | Professional CAD Design
Ball Valve — Variant 03
Brick Furnace Wagon 1 | Industrial CAD Design
Careta Protectoras/ Face Shield | 3D Engineering Design File
Bridg 2 | Industrial CAD Design
CAD CONVERSION FAQS
Everything to know before you convert.
Clear answers on conversion types, pricing, formats, output quality and private file handling.
Open the CAD converterWhat are the two types of CAD conversion on Marathon OS?
Marathon OS handles format-to-format conversion, such as STEP to STL, and 3D CAD to 2D drawing conversion, such as STEP or STP to a multi-view PDF, SVG or DXF drawing set.
Which CAD file formats can I convert?
Marathon OS supports STEP, STP, IGES, STL, OBJ, PLY, OFF, BREP, 3DM, DWG and DXF across more than 60 specialist conversion tools.
How much does a standard CAD format conversion cost?
A single standard conversion download costs $2.99. Credit packs reduce the per-download price further. One credit downloads one converted file of any supported size, and credits never expire.
How much does STEP or STP to 2D conversion cost?
A STEP or STP to 2D drawing conversion costs $5.99. The result can include multi-view technical drawing sheets in PDF, SVG and DXF formats, depending on the selected output.
Will a converted file keep every original CAD feature?
Not always. CAD-to-mesh conversion can remove parametric features, while mesh-to-CAD conversion may create reconstructed surfaces or approximations. Marathon OS shows these quality notes so you can choose the route with the right expectations.
How are uploaded engineering files handled?
Files are encrypted during upload, processed privately and automatically deleted after 7 days. Uploaded conversion files are not added to the public CAD library.
When should I hire a CAD designer instead of using a converter?
Use a converter when the geometry is correct and only the format or drawing output needs to change. Hire a CAD designer when geometry is missing, damaged, needs new tolerances, requires a native parametric rebuild or must be redesigned for manufacturing.