Your files
Viewing, conversion, editing, slicing and G-code analysis run in the tab; slicing uses a background worker of the same tab. The engines, including the 7.6 MB STEP engine, come from this domain. In a full test run that opened every tested format and ran all conversions, edits and G-code tools, every request went to our own origin, all were GET requests and nothing was posted. You can repeat the check in your browser's Network panel: the model file is never part of any request.
What your browser keeps
The list of recent files is stored in this browser (IndexedDB) so you can reopen a model. Your theme, units and slicer settings are remembered in local storage. The app also caches its own code and engines so that it opens faster next time. Clearing the site data in your browser removes all of it; none of it is sent to us.
The Chrome extension
When you open a link through the extension, it downloads that file from the site hosting it and hands it to the viewer tab inside your browser. The extension keeps its settings, the sites where you hid the badge and the last 10 files you opened in this browser, so you can reopen them from the side panel; clearing the list in the side panel or removing the extension deletes them. It records no browsing history and does not report which pages you visit.
Server logs
The web server that delivers the pages sees standard request data such as your IP address, browser and the page requested. These logs are used to keep the site running and are not combined with anything else.
Analytics: Yandex Metrica
The pages load the Yandex Metrica counter from mc.yandex.ru. It records page views, the referring page, clicks and scrolling (session replay), your approximate location from the IP address, the browser and the screen size, and it sets cookies for that purpose. It is the only script on the site that talks to another domain.
The tool also reports a few events to the counter so we can see which features are used: a file was opened, converted, downloaded, sliced or edited, and the calculator was used. Each event carries only the event name and file extensions such as stl or 3mf. File names, sizes, dimensions and the file contents never go to the counter or to us.
Session replay hides what you type in form fields. You can block the counter with a content blocker or by turning on Do Not Track in some browsers; the tool works the same without it. Yandex processes this data under its own privacy policy (yandex.com/legal/confidential).
Contact
Questions about this policy or a request about your data: support@stlview.app.