Privacy, explained.

The browser planner runs astronomy calculations on your device, without an account. It uses no analytics, tracking or cookies. Your saved sites, rigs, custom targets, preferences and horizons stay in your browser’s IndexedDB and localStorage. Importing a horizon file or restoring a backup does not upload that file to NightSeam.

Local storage is specific to the browser and site address. Clearing it removes saved planning data. Export a JSON backup first if you want to keep a separate copy; exported files remain wherever you save them.

Weather and air quality

Loading weather sends your active site’s latitude, longitude and selected timezone to the forecast and air-quality services at Open-Meteo. The requests also specify forecast variables and a four-day forecast period; your browser supplies normal connection information. Saved site names, equipment, custom targets and horizons are not included in these requests.

Weather loads when requested, or on startup if you enable “Always load on startup.” After you have loaded weather, changing the active site can fetch a new forecast. Disable the startup setting in the weather panel to prevent that automatic startup request. Weather data © Open-Meteo.com.

Object photos

Object details show available author, source and license credits. Opening an object without a cached photo can request an article summary and image credit metadata from Wikipedia and a thumbnail from Wikimedia’s image service. Those services receive the requested article or image path and normal connection information; saved observing coordinates, rigs and horizons are not sent with photo requests. Downloaded thumbnails are cached locally in IndexedDB. Each image retains its own license and credit requirements.

Using your location

The “use my location” button asks your browser for your position only when you press it, subject to the browser’s permission controls. The browser’s own location service may use network services. The resulting coordinates are stored locally as site data and can subsequently be sent to Open-Meteo if you load weather for that site.

When you capture a horizon and your browser already allows location access for this site, the capture compares your position with the observing site to warn when you are far from it. It never asks for your location itself, and that position is neither stored nor sent.

Camera and motion sensors

Capturing a horizon on a phone asks your browser for the camera and, where the browser requires it, for the motion sensors. The camera image is shown on screen and, where the browser supports it, measured on your device to keep the overlay in step with your movement; it is never recorded, stored or uploaded. Only the skyline points you trace are saved. Each phone keeps its own overlay timing and scale in localStorage.

Share links

A share link carries a horizon’s name, skyline points and overhang edges in the part of the address after “#”, which browsers do not send to the website. Anyone you give the link to can read that horizon, and the app you share it through handles it under its own terms. Opening a link asks before the horizon is added.

Website requests

Opening the site or planner requests pages, scripts, catalog files and site graphics from the website’s host. These requests expose technical connection information such as your IP address and browser request headers. The catalog and Standard selection are prepared in advance and served by this website; browsing them does not contact a separate catalog provider.

Hosting

This site is hosted by ZAP-Hosting GmbH, without a content delivery network (CDN). The host and external services may process technical request data to deliver their responses.

Website access and error logs can contain your IP address, the time of the request, the requested URL, response status and transferred data size. The website’s own logs rotate daily and are kept for about eight days (the current log plus up to seven archived ones). IP addresses are not anonymized in this configuration. This describes the website’s logs, not any separate records maintained by the hosting provider.

Open the planner online and let the catalog finish loading. Planning can then continue in that open tab while disconnected. Offline reopening or reloading is not guaranteed. Weather and uncached external photos need an internet connection.

For questions about request logs, retention or saved planning data, contact the operator →.