wishlist: offline modus

[zion2k]

Hello,
first of all: I love your simple and clean map viewer.
Due to the poor mobile reception (here in Germany), I often have no data reception or only EDGE which is not really useable. It would be nice to have the option to save a area or use prepared area/images for these situations. Mordern mobile phones should have enough space to save a whole country without a problem.
Also nice would be an option that if I use a gpx file I could safe the area of the gpx file for offline usage. I nice feature if I would make a pre-planed a tour.

[skarn958]

You can preload them into the external storage of the app. I guess that would also solve the problem.

Pygmalion wrote an article on how to do it: https://pygmalion.nitri.org/preloading-offline-maps-in-opentopomap-viewer-1714.html

[jonahhes]

You can preload them into the external storage of the app. I guess that would also solve the problem.

Pygmalion wrote an article on how to do it: https://pygmalion.nitri.org/preloading-offline-maps-in-opentopomap-viewer-1714.html

I can not get this to work for the life of me. I tried both methods mentioned in the blog post with no success. When I start the app in airplane mode, it always opens empty with no tiles and does not seem to load anything from the preloaded offline tiles.
@Pygmalion69 Is your blog post outdated or I am doing something wrong?

[Pygmalion69]

@jonahhes You are not doing anything wrong. The old preload method became unreliable due to newer Android storage restrictions and an osmdroid preload/import bug that was never properly fixed before the project was archived.

Because of that, we have now implemented a new interactive offline tile import in OpenTopoMap Viewer itself. You can now select a ZIP file through Android’s file picker and the app imports the tiles directly into the offline SQLite cache used by osmdroid.

Supported ZIP layouts:

• OpenTopoMap/{z}/{x}/{y}.png
• {z}/{x}/{y}.png

Screen_recording_20260514_191542.mp4