How to open a .AT5 file online
From file to map in seconds.
Open your .AT5 file
Drag it onto the box or click to choose it from your device. It opens on your computer.
See it on the map
Points, lines and areas from your .AT5 file appear on an interactive map. Click any feature to read its details.
Read the stats
Check distance, elevation gain and loss, the bounding box and a height profile linked to the map.
What is a .AT5 file?
The common language of GPS devices.
An AT5 file is a Navico Atlas Type 5 chart for Lowrance, Simrad, and B&G marine GPS chartplotters. To use it, copy the at5.xml file, all .at5 data files, and the ShadedRelief/ folder to the root of a microSD card and insert it into your chartplotter. Commercial Navico Insight charts are device-locked to a specific chartplotter serial number; custom charts made with free tools are not.
Programs that open .AT5 files
| Full name | Navico Atlas Type 5 Chart File |
|---|---|
| Developer | Navico (parent company of Lowrance, Simrad, B&G brands) |
| First released | Approximately 2008–2010 (Navico Insight mapping era) |
| Category | Maps & GIS |
| MIME type | application/octet-stream |
| Signature | 55 AA 05 00 (U«..) |
Related viewers
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Is my .AT5 file uploaded anywhere?
No. Your .AT5 file is read by your browser and never sent to us. Only the background map tiles are loaded from OpenStreetMap, which sees which map area you're looking at, not your data.
How is the elevation gain calculated?
We add up every climb between track points, ignoring tiny wiggles of less than 3 metres that come from GPS noise. That's close to what Strava and Garmin report; barometric devices may differ slightly.
How do I open a Shapefile?
A Shapefile is several files. Drop the whole .zip, or select the .shp, .dbf and .prj files together. With only the .shp you'll see the shapes but no attributes.
Can I convert GPX to KML or GeoJSON?
Use Export GeoJSON to save everything you see. GPX ↔ KML conversion is part of our upcoming converter.
My CSV has coordinates. Will it work?
Yes, if it has columns named like lat/latitude/y and lon/lng/longitude/x. Every row becomes a point with the other columns as properties.
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