Offline Maps for Hiking: What to Check Before You Lose Signal
Offline maps for hiking compared by what they can and can't do without signal. Google Maps (no walking directions offline), Organic Maps, and a pre-trip checklist.
By TrailsPals · Source-based guide. How we prepare our guides · Suggest a correction
Phone GPS works without signal. The map under it usually does not, unless you downloaded it first. This post covers what offline maps actually do, two options whose own documentation we read, and a short check to run at home before you rely on any of them.
Do offline maps work without cell signal?
Yes, if the area was downloaded beforehand. Your phone's GPS receiver needs no data connection, so a downloaded map can show your position with no signal. But each app decides which features still work offline, and some of them, like walking directions, may not.
What do Google Maps offline maps do and not do?
Google's help page for offline maps says that once you download an area, "If your internet connection is slow or unavailable, your offline maps can guide you to your destination as long as the entire route is within the offline map." The catch for hikers is in its tip: "When you're offline, transit, bicycling, or walking directions are unavailable."
Other points from that page:
- Downloads expire. "You must update the offline maps you've downloaded on your phone or tablet before they expire." When an area is within 15 days of expiring and you are on Wi-Fi, Google Maps tries to update it automatically, and there is an auto-update setting. The page does not state the full lifetime of a download.
- The page gives no maximum area size.
- Some regions cannot be downloaded "because of contractual limitations, language support, address formats, or other reasons."
- You need to be online (and on iPhone, not in Incognito mode) when you download.
So Google Maps can show where you are on a downloaded map, which helps you orient yourself, but do not count on turn-by-turn walking guidance from it without signal.
What about a free, OpenStreetMap-based offline app?
Organic Maps describes itself on its website as a "privacy-focused offline maps & GPS app for hiking, cycling, biking, and driving" that supports "100% of features without an active Internet connection" once you download maps. It says it is powered by OpenStreetMap data, is free and open source (Apache License 2.0), and lists hiking trails, walking paths, contour lines and elevation profiles among its features. Those are the app's own claims, and we did not test it. Coverage and trail detail depend on how well OpenStreetMap maps your area, so check your trail there before the trip.
What about Apple Maps, AllTrails, and Gaia GPS?
We tried to read Apple's offline maps article, AllTrails' help pages and Gaia GPS's help site while writing this. The Apple article body would not load, and the AllTrails and Gaia GPS help pages were blocked or unavailable. We are not going to describe their offline features from memory. Check each app's current help page for which plan or version offline maps need, how big a download can be, and whether routing works offline.
How do you check your offline map before you leave?
Do this at home, on Wi-Fi, with the same phone you will carry:
1. Download the whole area, not just the trailhead. Include the access road and any bail-out routes.
2. Put the phone in airplane mode and open the map. Confirm your trail shows and your position dot appears.
3. Search for the trailhead and a landmark while offline. Note whether search and directions still work.
4. Check the expiry date or update status, and update on Wi-Fi if the map is close to expiring.
5. Make sure the download is on the device storage the app reads from, and that you have free space left.
If any step fails in airplane mode, it will fail on the trail.
What else do you need besides the map?
A map only helps while the phone has power. Carry a power bank, and keep a way to find your way that does not depend on the phone, as covered in phone GPS vs a dedicated GPS device. Also read how accurate phone GPS is on trails, since a good map with a poor fix under tree cover still misleads.
Offline maps help you, but they do not tell anyone else where you are. Before you lose signal, leave an expected return time with someone. The hiking safety app page explains how TrailsPals handles that for the person waiting at home. Live sharing needs signal to update, so it supplements a plan and a downloaded map, not replaces them.
Summary
Download the whole area before the trip, test it in airplane mode, and know which features stop working offline. Google Maps, per its own help page, gives no walking directions offline. Verify any other app's offline claims on its current help page.