[{"data":1,"prerenderedAt":-1},["ShallowReactive",2],{"extension:v3:en:step":3},{"resolvedFromAlias":4,"canonicalExt":5,"ext":5,"name":6,"category":7,"categoryName":8,"updatedAt":9,"popularity":10,"summary":11,"howToOs":12,"quickAnswer":18,"answerIntro":19,"whatIs":20,"description":21,"furtherReading":22,"openInstructions":38,"commonIssues":51,"securityNotes":71,"faq":75,"aliases":88,"mimeTypes":91,"relatedExtensions":94,"breadcrumbs":129,"categoryAnchor":139,"categoryFuturePath":140,"metaDescription":141,"availableHowToOs":142,"openOnDeviceLinks":143,"cannotOpenReasons":159,"cannotOpenFixes":160,"convertOptions":161,"securityAffiliateMessaging":162,"securityAffiliates":163},false,"step","STEP (ISO 10303-21) CAD exchange file","cad","CAD","2026-06-12T08:24:56.053Z",70,".step is a widely used neutral CAD exchange format for sharing 3D product model data between different CAD systems. You typically open it by importing it into a CAD program such as Autodesk Fusion.",[13,14,15,16,17],"windows","mac","linux","ios","android","To open .STEP files on Windows, open Autodesk Fusion.","To open a .step file, import it into a CAD application that supports STEP (ISO 10303-21), such as Autodesk Fusion. If double-clicking doesn’t work, open your CAD app first and use its Import/Open workflow for STEP.","A .step file is a STEP-file as defined by ISO 10303-21, commonly used to exchange product model data (often 3D geometry) between CAD systems. STEP files are typically ASCII text files with a defined structure for representing product data, and the common extensions include .stp and .step.","STEP (ISO 10303) is an international standard designed for exchanging product model data across different systems and organizations. Its goal is long-term, system-independent representation of product data to support design, manufacturing, and related engineering workflows.\n\nThe file type commonly referred to as “a STEP file” is often a STEP-file per ISO 10303-21 (the clear-text encoding for exchanging instances of the data model). In practice, engineers use .step/.stp to move CAD models between tools without relying on a single vendor’s native format.\n\nBecause STEP is used as an interchange format, a common workflow is importing the file into a CAD tool, then validating geometry/features and saving into the tool’s native project format. When exchange goes wrong, the most frequent issues are incomplete/partial imports, unit/scale mismatches, and confusion with other similarly named “step” files that are unrelated to CAD.",[23,26,29,32,35],{"title":24,"url":25},"IANA Media Types (STEP: model/step and model/step+xml)","https://www.iana.org/assignments/media-types/index.html",{"title":27,"url":28},"STEP-file, ISO 10303-21 (Library of Congress Format Description)","https://www.loc.gov/preservation/digital/formats/fdd/fdd000448.shtml",{"title":30,"url":31},"Introduction to ISO 10303 - The STEP Standard for Product Data Exchange (NIST)","https://www.nist.gov/publications/introduction-iso-10303-step-standard-product-data-exchange",{"title":33,"url":34},"File formats supported in Autodesk Fusion (STEP import support)","https://help.autodesk.com/view/fusion360/ENU/?caas=caas%2Fsfdcarticles%2Fsfdcarticles%2FFile-formats-supported-by-Fusion-360.html",{"title":36,"url":37},"How to import or open a STEP file in Autodesk Fusion 360 (Autodesk Support)","https://www.autodesk.com/support/technical/article/caas/sfdcarticles/sfdcarticles/How-to-import-or-open-a-step-file-in-Autodesk-Fusion-360.html",{"windows":39,"macos":42,"linux":44,"ios":47,"android":49},[40,41],"Open Autodesk Fusion.","Use Fusion’s import/open workflow to import the .step/.stp file (STEP is listed as a supported format).",[40,43],"Import the .step/.stp file using Fusion’s supported file import/open workflow for STEP.",[45,46],"If you don’t have a STEP-capable CAD tool on your Linux system, transfer the file to a Windows or macOS machine with a CAD app (for example, Autodesk Fusion) and import it there.","Confirm the file is a real ISO 10303-21 STEP file (it is typically ASCII text) before troubleshooting the CAD import.",[48],"On mobile, STEP opening support varies; if you can’t open it locally, transfer the .step file to a desktop CAD application (for example, Autodesk Fusion) and import it there.",[50],"If your device doesn’t have a STEP-capable CAD viewer, move the .step file to a desktop CAD program (for example, Autodesk Fusion) and import it there.",[52,58,65],{"title":53,"description":54,"steps":55},"File won’t open by double-clicking (no associated app)","Many systems don’t have a default app association for STEP, so double-clicking may do nothing or prompt you to choose an app.",[56,57],"Open a CAD program that supports STEP (for example, Autodesk Fusion).","Use the program’s Import/Open function to load the .step file rather than double-clicking it.",{"title":59,"description":60,"steps":61},"Import fails or shows an empty/partial model","Interchange imports can fail due to unsupported data from a particular STEP application protocol or differences in what the importer expects.",[62,63,64],"Verify you are importing a STEP CAD file (.step/.stp) and not an unrelated file that happens to use the word “step”.","Try importing the same file using Autodesk Fusion’s STEP import workflow and confirm STEP is supported for import in Fusion.","If you have access to the exporting system, re-export to STEP again and retry the import.",{"title":66,"description":67,"steps":68},"Wrong size or units after import","CAD exchange sometimes results in unit/scale mismatches, making the model appear too large or too small after importing.",[69,70],"Check the model’s expected units in the originating CAD system or documentation.","After importing, verify the scale/units settings in your CAD tool and adjust if necessary.",[72,73,74],"STEP (ISO 10303-21) files are typically ASCII text and are not intended to contain executable code, but they can still trigger vulnerabilities in CAD importers/parsers if the file is malformed or maliciously crafted.","Only open .step files from trusted sources, especially in high-value engineering environments, because importing untrusted CAD exchange files can be a practical attack surface against complex CAD software.","If a .step file was delivered inside an email or downloaded from an unknown site, consider validating it in a controlled environment before importing it into production CAD workflows.",[76,79,82,85],{"question":77,"answer":78},"Is .step the same as .stp?","Yes. Both .step and .stp are commonly used filename extensions for STEP-files (ISO 10303-21).",{"question":80,"answer":81},"What MIME type should a STEP file use?","IANA lists registered media types for STEP, including model/step and model/step+xml.",{"question":83,"answer":84},"How do I import a STEP file into Autodesk Fusion?","Autodesk provides a dedicated support article with step-by-step instructions for importing/opening .step/.stp in Fusion 360, and Fusion’s supported formats list includes STEP (*.ste, *.step, *.stp).",{"question":86,"answer":87},"Is a STEP file text or binary?","A STEP-file per ISO 10303-21 is defined as an ASCII text encoding for STEP data.",[89,90],"stp","ste",[92,93],"model/step","model/step+xml",[95,100,106,112,118,124],{"ext":89,"name":96,"category":7,"categoryName":8,"popularity":97,"summary":98,"howToOs":99},"STEP (ISO 10303) Part 21 CAD exchange file",72,".stp is a STEP (ISO 10303) 3D CAD exchange file, typically a STEP physical file per ISO 10303-21 (Part 21). It’s commonly used to transfer 3D product geometry between CAD systems.",[13,14,15,16,17],{"ext":101,"name":102,"category":7,"categoryName":8,"popularity":103,"summary":104,"howToOs":105},"ifc","Industry Foundation Classes (IFC) BIM exchange file",55,".ifc is an open Building Information Modeling (BIM) exchange format used to share building and infrastructure models between different design, construction, and facility-management applications.",[13,14,15,16,17],{"ext":107,"name":108,"category":7,"categoryName":8,"popularity":109,"summary":110,"howToOs":111},"cdr","CDR CAD drawing",43,".CDR is the native drawing document format for CorelDRAW, commonly used for vector graphics, page layout, and print workflows. The most reliable way to open it is with CorelDRAW on a desktop computer.",[13,14,15,16,17],{"ext":113,"name":114,"category":7,"categoryName":8,"popularity":115,"summary":116,"howToOs":117},"cgm","CGM CAD drawing",42,".CGM (Computer Graphics Metafile) is an ISO/IEC 8632 standard graphics metafile that can store 2D vector graphics, raster graphics, and text. It is commonly used for technical illustrations and interchange between systems that support CGM.",[13,14,15,16,17],{"ext":119,"name":120,"category":7,"categoryName":8,"popularity":121,"summary":122,"howToOs":123},"dwg","AutoCAD Drawing File",41,".DWG is a CAD drawing format best known as AutoCAD’s native drawing file, used for 2D/3D design and technical documentation. Open it with Autodesk AutoCAD or a DWG viewer such as Autodesk DWG TrueView.",[13,14,15,16,17],{"ext":125,"name":126,"category":7,"categoryName":8,"popularity":121,"summary":127,"howToOs":128},"dxf","CAD Exchange Drawing (DXF)",".DXF is Autodesk’s Drawing eXchange Format, widely used to exchange 2D/3D CAD drawings between different applications. It’s commonly opened and edited in CAD programs such as AutoCAD-compatible tools and LibreCAD.",[13,14,15,16,17],[130,133,136],{"label":131,"to":132},"Home","/",{"label":134,"to":135},"File Extension Index","/file-extension",{"label":137,"to":138},".STEP","/file-extension/step","category-cad","/category/cad","Learn what .STEP files are, how to open them on every platform, common fixes, and security best practices.",[13,14,15,16,17],[144,147,150,153,156],{"os":13,"label":145,"to":146},"Open .STEP on Windows","/how-to/open-step-on-windows",{"os":14,"label":148,"to":149},"Open .STEP on Mac","/how-to/open-step-on-mac",{"os":15,"label":151,"to":152},"Open .STEP on Linux","/how-to/open-step-on-linux",{"os":16,"label":154,"to":155},"Open .STEP on iOS","/how-to/open-step-on-ios",{"os":17,"label":157,"to":158},"Open .STEP on Android","/how-to/open-step-on-android",[53,59,66],[56,57],[],"untrusted_source",[164,168],{"name":165,"description":166,"affiliateUrl":167},"Avast","Avast offers free and premium antivirus software that protects against viruses, malware, ransomware, and phishing. Scan files before opening them to ensure safety.","https://www.avast.com/lp-aff-consumer-store?expid=inf601",{"name":169,"description":170,"affiliateUrl":171},"Norton","Norton 360 delivers comprehensive antivirus protection, VPN, and identity theft monitoring. Scan files for threats before opening to keep your device secure.","http://buy.norton.com/aff_home?utm_campaign=en-ww_nor_n36_aff_nas_nau_nah_cj_nad_low:_sec_nat_mktc_norton_360"]