A free GeoPDF viewer for Android

A GeoPDF is a PDF map with coordinates built in: Forest Service MVUMs, USGS topo quads, park and trail maps, hunting unit maps. A plain PDF reader shows the picture. A GeoPDF viewer also reads the coordinates, so it can draw a dot where you are, measure distances and record your track on the map itself.

Your phone’s GPS works from satellites, not from cell towers, so once a map is on the phone it works anywhere.

1. Open app.cartahaven.com in Chrome.
2. Tap Install (or ⋮, then Install app). It opens from your home screen like any other app, offline too.
3. Tap Import and pick a GeoPDF from your phone (Downloads, Drive or a USB stick), up to 500 MB. It shows your position straight away.
4. Open the map once with airplane mode on, to check it is on the phone before you lose signal.

No account is needed to open your own files. A free account lets you get maps from the store and back up your tracks.

• GeoPDF and georeferenced PDF (including map books with several pages), free.
• GeoTIFF, free.
• A plain PDF, scan or photo of a map: place it yourself by matching three or more spots to a world map (how), free.
• MBTiles and GeoPackage raster tiles, with Cartahaven Plus ($9.99 a year).
• Tracks and placemarks as GPX, KML, KMZ, GeoJSON, CSV or shapefiles, and export as GPX, KML or GeoJSON.

While you are online, the app also saves a background map, elevation and, in the US, public land boundaries around each map, so you still see where you are a little past the edge of the sheet. Free in the app: hunting units for many states and legal shooting light, a UTM or MGRS grid, walking a compass bearing, a red-light night mode, “Where am I, in words” for a radio or 911 call, trip check-in, voice cues, and wildfires and avalanche danger over the map. Plus adds offline satellite imagery, weather radar, river gauges, snow depth and a 1 GB backup with photos.

• Screen off: Android stops GPS for a web app when the screen is off. While you record a track the app keeps the screen on; dim it to save battery.
• Storage: maps live in Chrome’s storage for the app. Clearing Chrome’s site data for app.cartahaven.com removes them; store maps download again from “My purchases”.
• Accuracy: usually a few meters in the open. The map is only as accurate as its maker drew it; carry a paper map and compass too.

The Android app is built and coming to Google Play; it is not there yet. Leave your email and we will tell you once, when it is out.