Open SXF(P21) files in your browser
P21 is the formal file type of SXF, Japan's public-works CAD standard, based on ISO 10303 (STEP). If you received .p21 deliverables from a Japanese client and have no way to open them, zumen-gate displays them right in your browser.
Can't open a SXF(P21) file? Common causes and fixes
You received P21 deliverables but have no software that opens them
Drop the file here to inspect the contents — no procurement needed.
You need the drawing in your own CAD
Convert it to DXF here, or export a PDF for circulation.
Convert it while you're here
A displayed SXF(P21) file can be converted straight to DXF, PDF, SVG, or PNG — and the loss report shows exactly what survived the conversion.
FAQ
SXF(P21) viewer — frequently asked questions
How do I open a P21 file in AutoCAD?
Use the P21 to DXF conversion. R2010 (AC1024) output suits AutoCAD; R12 (AC1009) suits older CAD software.
Is a .p21 file the same as a STEP file?
They share the ISO 10303-21 container format, but SXF P21 files carry 2D CAD drawing data under the Japanese SXF standard — so generic STEP/3D viewers usually can't display them meaningfully. This viewer reads them as SXF drawings.