Free. Open source. Plans included.
No account, no subscription, nothing to buy. Design, check and download the build-ready plan for every catio you make — and read the code that makes it.
Design
- Every template: lean-to, freestanding, window box and tunnel
- Fit it to your wall, window or yard
- Cats, enrichment and cat-safe plants
- Save in your browser, export the project file
Check
- Safety and welfare checks with sources
- Measurement confidence review
- Share a view-only link
- iPhone, iPad and Mac app when it launches
Build-ready plan
- Materials list and cut list
- Cost range from dated prices
- Assembly steps and inspection checkpoints
- PDF package and CSV (needs confirmed dimensions and no blockers)
Open source, MIT licence
The web planner is public on GitHub: the editor, the generator that turns your design into framing, mesh and fixings, every safety and welfare check with its source, the build plan, and the Catio Quest and Catio Prowl games. Nothing about a cut list or a check result is hidden — you can see exactly how it was worked out, run your own copy, or suggest a fix.
Questions
Is OpenCatio3D open source?
The web planner is: the editor, the parametric generator that turns a design into parts, the safety and welfare checks, the build plan, and the Catio Quest and Catio Prowl games. It is MIT-licensed on GitHub, so you can read how every check and cut list is worked out, run it yourself, or send a fix. The iPhone, iPad and Mac app and this website are not published yet.
Is the build-ready plan really free?
Yes. The materials list, cut list, cost range, assembly steps and PDF are free for every project, as many as you like. It is only held back while a design has a blocker or unconfirmed key dimensions — for safety, not payment.
Is there a paid tier or subscription?
No. There is nothing to buy and no account to create. Builder tools such as client projects and branded exports are planned; see for builders.
Do you sell my data or show ads?
No. There are no ads, designs stay on your device, and analytics (on the website and planner) only runs if you allow it. See the privacy policy.
Do partners pay to appear in recommendations?
Not today. If affiliate or partner products are added later they will be clearly labelled, and sponsorship will never change a safety finding.
Design your catio in your browser
Free to design and check. Fit a catio to your wall, window and yard, run the safety checks, and see the materials list before you buy a single board.