A free CATIA viewer for CATPart and CATProduct files — no CATIA licence needed
PartLens opens CATIA V5 parts (.CATPart) and assemblies (.CATProduct) for free, offline, on Android and Windows — no CATIA seat, no account, no upload. It places every part of an assembly, names it as CATIA's tree does, and lets you measure and section it. Measurements on CATIA files are approximate (≈); for exact numbers, open a STEP export.
CATIA files reach tool rooms, die shops and suppliers every day, usually from someone who has a CATIA licence to someone who does not. Until now the choice was a paid viewer, a cloud upload of customer geometry, or asking the sender for a STEP file and waiting. PartLens 2.31 opens the CATIA file itself, on the device you already have.
What PartLens opens
- Parts (.CATPart) — solids and surfaces, as CATIA displayed them when the file was saved.
- Assemblies (.CATProduct) — every part placed where CATIA puts it, sub-assemblies included, with CATIA's own instance names in the parts tree.
- Every CATIA V5 release from V5R19 (2009) to V5-6R2024 — checked on more than 400 real production parts and nearly 100 assemblies saved by ten different releases.
- Renamed files — PartLens recognises a CATIA file by its content, so a part forwarded as part.stp still opens as CATIA.
How a free viewer can read CATIA
Every CATIA V5 part carries two things: CATIA's exact geometry, and a ready-made triangle display shape that CATIA uses to draw the part quickly. PartLens reads the display shape. That is why it needs no CATIA software, and also why its measurements on CATIA files are marked approximate (≈) — the same honest label PartLens gives STL files. Hole positions on the display shape match CATIA's own to a hundred-thousandth of a millimetre in our checks, but PartLens does not claim exactness it cannot prove.
Opening a whole assembly
A .CATProduct holds no geometry; it lists the part files it uses and where each one sits. So PartLens needs the parts too:
- On Windows, keep the .CATPart files in the same folder as the assembly and open the .CATProduct.
- On a phone, send the assembly's folder as one .zip and open the zip. PartLens finds the top assembly and places every part.
- If a part file is missing, PartLens names it instead of silently leaving a gap.
Step-by-step instructions are in how to open CATPart and CATProduct files.
Honest limits
| File | What PartLens does |
|---|---|
| CATIA V5 .CATPart / .CATProduct | Opens, places, measures (≈) and sections |
| Part saved with its bodies hidden | No display shape is stored, so PartLens says so and suggests showing the bodies and saving, or a STEP export |
| Exact CATIA geometry | Not read; for exact numbers open a STEP export |
| .CATDrawing, CATIA V4 .model, 3DEXPERIENCE data | Not opened |
PartLens is a viewer: it never changes or re-saves your CATIA files.
Where to get it
CATIA support arrives in PartLens 2.31: on Windows as a free download, and on Android through Google Play (if an existing install doesn't open .CATPart yet, update it). The free Windows PartLens Converter can also package CATIA files for phones. The Mac beta gains CATIA support in its next build.
Frequently asked questions
Is PartLens really free for CATIA files?
Yes. PartLens is free on Google Play and as a Windows download, with no ads, account or subscription, and CATIA files are included.
Can I open a CATPart file without CATIA installed?
Yes. PartLens reads the display shape stored inside the CATPart, so no Dassault software is needed on the phone or PC.
Why does PartLens say a CATIA part has no display shape?
CATIA only stores a display shape for bodies that were visible when the part was saved. If every body was hidden, there is nothing to show. In CATIA, show the bodies and save again, or ask for a STEP export.
Which CATIA versions are supported?
CATIA V5, checked on files saved by V5R19 (2009) through V5-6R2024. When a file can't be shown, the message names the CATIA release that saved it.
Are my CATIA files uploaded anywhere?
No. Files are read on your device and never uploaded. There is no account and no cloud processing.
Open the CATIA file you just received
Free and offline on Android and Windows. No CATIA seat, no upload.
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