Elevation values come from the free, community-run Open-Elevation public API when reachable; if that request fails or times out, the profile is left unfetched and flagged so you can retry rather than showing a made-up estimate. Map tiles are free OpenStreetMap tiles, and place search uses the free Nominatim geocoder. This is a route-elevation planning tool, not a live GPS hiking tracker - no position tracking, no offline maps, no turn-by-turn guidance.