How to view a .P21 file online
From email attachment to readable drawing in seconds.
Choose your file
Drop your .P21 file onto the box above, or click to browse for it.
It opens right away
Your .P21 file is read and drawn right in the page: 2D drawings layer by layer, 3D models and building files as a shape you can orbit.
Explore and measure
Pan, zoom and toggle layers, measure distances, hide walls in a building model, export the drawing as SVG or PNG.
What is a .P21 file?
Drawings, solids and buildings: three very different kinds of "CAD".
A .P21 file is a PAR recovery volume used for backup purposes. These files typically contain 3D data and are designed to assist in the restoration of information. They are commonly opened and managed using the QuickPar utility.
Programs that open .P21 files
| Full name | STEP Part 21 Exchange File (ISO 10303-21) |
|---|---|
| Developer | ISO (International Organization for Standardization) |
| First released | 1994 (ISO 10303-21); .p21 designated for general Part 21 exchange files |
| Category | 3D & CAD |
| MIME type | model/step |
Related viewers
More free tools for engineering files.
Is my .P21 file uploaded to your server?
No. Your .P21 file is parsed and drawn for you.
Can you open DWG drawings?
Yes. We decode AutoCAD DWG files (R13 up to the 2018 format) with LibreDWG and draw the real geometry, layers and text. A few DWGs that use features we don't draw yet fall back to the preview image AutoCAD stores inside the file; for those, saving as DXF (File › Save As › DXF) also works.
How do I measure a distance?
Turn on Measure, click the first point, then the second. The distance is shown in the drawing's units, which we read from the file header.
Some text or hatching is missing. Why?
The online viewer draws lines, curves, text, blocks and solids. Hatch patterns, dimension styles and proxy objects from add-ons are simplified or skipped.
Can I see properties of building elements?
Yes. In an IFC model, click any wall, slab, door or window to see its type, name and GlobalId. Use the element types list to hide whole categories, for example walls, to look inside.
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