What’s the best free mapping stack for a student delivery app with offline support?

Be careful with public geocoding services. Nominatim is useful for occasional lookups, but it generally isn’t suitable for autocomplete requests as someone types and has strict rate limits. Photon is a better fit for search-as-you-type, especially if you can self-host it. Cache completed address lookups, send a clear application identifier, and keep requests low. OpenRouteService is another reasonable option for online routing and geocoding if its daily limits cover your demo, while self-hosted OSRM or Valhalla avoids request quotas.

A practical open-source stack would be MapLibre for rendering, Photon for address search, and OSRM or Valhalla for routing. For offline map display, generate a PMTiles archive containing only your delivery region and bundle it with the PWA. That keeps the download manageable and avoids running a tile server. The public OSRM demo or a hosted routing API may be fine during development, but self-hosting a regional OSRM or Valhalla instance is more reliable if you need predictable limits.

For a zero-budget proof of concept, keep the geographic area small instead of trying to support an entire country. Use MapLibre with a locally bundled PMTiles file for the map, and run routing locally with OSRM or Valhalla. You can use an online service during early development, then switch to a regional self-hosted setup before the final demo. That approach gives you offline fallback without relying on commercial tile caching rules or risking surprise billing.

The offline requirement is the part that rules out many otherwise generous free tiers. MapLibre plus PMTiles can handle offline vector maps, but remember that the tiles are only one piece: you also need to package the style file, fonts, and icon sprites or the offline map may appear blank. Offline routing is separate from offline map display, so you’ll need a local routing graph too if drivers must get directions without a connection. For a small region, a Valhalla or OSRM extract should be manageable.