Privacy policy
Last updated October 28, 2026
MiniMarbleRuns is run by Capital Coders Inc. (“we”). We don’t show ads, we don’t sell or rent personal information, and we only collect what we need to run and improve the site.
Your designs are made in your browser
The marble run generator, the physics simulation and the STL / 3MF exports all run on your own device. Your settings and the 3D files you download are not uploaded to us unless you choose to publish a run to the gallery or attach a design to a support message.
What we collect
Visit statistics
We run our own analytics (no Google Analytics or other third-party trackers). For each page view we record the page, the referring website, campaign tags in the link (such as utm_source), your browser, operating system and device type, screen size, language and time zone. Your country is taken from your browser language, or from your connection if the site is served through Cloudflare.
We do not store your IP address. To count unique visitors and stop abuse we keep a one-way hash of it that changes every day, so it can’t be linked across days or turned back into an address. Automated visitors (bots) are only counted, not recorded.
How the generator is used
We record events such as “generated a run”, “dropped a marble”, “downloaded a 3MF” or “changed the slope”, with the settings involved (style, marble size, file format and similar). This tells us which features people use and what to improve. JavaScript errors are recorded so we can fix bugs.
Gallery submissions
When you publish a run we store the name and author name you enter, your design settings, a thumbnail picture of the model and basic statistics (size, track length). Published runs are public. Views, likes and downloads of gallery runs are counted per visitor.
Support messages
If you contact us we store your name, email address, message, the page you sent it from and, if you tick the box, your current design settings.
Payments
If you buy anything from us, payment is handled by Stripe. Stripe receives your card details; we never see or store them. We receive your email address, what you bought and the payment status, and we store your licence key with your email address and the Stripe reference numbers so we can activate, renew and recover your licence. When you activate or use a licence key, your browser checks it with our server about twice a day.
Server logs
Our web host keeps standard server logs (including IP addresses) for security and troubleshooting, under its own retention policy.
Cookies and browser storage
| Name | What it’s for | Expires |
|---|---|---|
mmr_vid | A random visitor ID used to count unique visitors and remember gallery likes. | 1 year |
mmr_sid | A random session ID used to group page views into one visit. | 30 minutes of inactivity |
mmr_params_v1 (local storage) | Remembers your last design on this device. Never sent to us. | Until you clear it |
mmr_license (local storage) | Remembers your licence key on this device. | Until you clear it |
| Admin session | Only set for site staff signing in to the statistics dashboard. | End of session |
These cookies are first-party, contain no personal details and aren’t used for advertising.
Services your browser connects to
- jsDelivr (cdn.jsdelivr.net) — delivers the 3D library (three.js), the label font and the dashboard charts.
- Google Fonts — delivers the Inter and Space Grotesk fonts.
- Stripe — only when you make a payment.
Like any website, these services receive your IP address and browser details when they deliver files.
How we use information
- To run the site, the gallery and share links.
- To understand, in aggregate, how the generator is used and what to improve.
- To prevent spam and abuse (for example, rate-limiting gallery uploads and messages).
- To answer your messages and handle purchases.
How long we keep it
- Visit statistics and usage events: up to 25 months, then deleted automatically.
- Support messages: up to 24 months.
- Published gallery runs: until you ask us to remove them, or we remove them.
- Licences: for as long as the licence exists, so you can recover your key.
- Payment records: as long as tax and accounting law requires.
Your choices and rights
You can block or delete cookies in your browser and the generator will keep working. You can ask us to access, correct or delete personal information we hold about you, or to take down a run you published, through the support page. Depending on where you live you may have further rights under Canada’s PIPEDA, the EU/UK GDPR or California’s CCPA, and you may complain to your local data-protection authority.
Where data is stored
Our servers may be outside your country. We protect data with HTTPS, restricted access and by not storing more than we need.
Children
The site is suitable for all ages, but children under 13 should not publish runs or contact us without a parent. Remember that steel balls and magnets are choking hazards.
Changes
If we change this policy we’ll update the date at the top. Significant changes will be noted on the site.
Contact
Capital Coders Inc. — use the support page and choose “Privacy or data request”.