diff --git a/index.html b/index.html
index 5bcfb7c..d0f8399 100644
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@@ -281,10 +281,10 @@ can use it in GPXSee.</small></p>
 <tr>
 <td><a href="maps/OpenStreetMap-Switzerland.xml" download><img src="tiles/OpenStreetMap-Switzerland.png" alt="Map Preview" width="256" height="256"/></a><br/>OSM Switzerland</td>
 <td><a href="maps/OpenStreetMap-Swiss-Style.xml" download><img src="tiles/OpenStreetMap-Swiss-Style.png" alt="Map Preview" width="256" height="256"/></a><br/>OSM Switzerland Swiss Style</td>
-<td><a href="maps/Swisstopo-25k.xml" download><img src="tiles/Swisstopo-25k.png" alt="Map Preview" width="256" height="256"/></a><br/>Swisstopo - 25k</td>
-<td><a href="maps/Swisstopo-Landeskarte.xml" download><img src="tiles/Swisstopo-Landeskarte.png" alt="Map Preview" width="256" height="256"/></a><br/>Swisstopo - Landeskarte</td>
+<td><a href="maps/Swisstopo-25k.xml" download><img src="tiles/Swisstopo-25k.jpg" alt="Map Preview" width="256" height="256"/></a><br/>Swisstopo - 25k</td>
+<td><a href="maps/Swisstopo-Landeskarte.xml" download><img src="tiles/Swisstopo-Landeskarte.jpg" alt="Map Preview" width="256" height="256"/></a><br/>Swisstopo - Landeskarte</td>
 </tr><tr>
-<td><a href="maps/Swisstopo-Swissimage.xml" download><img src="tiles/Swisstopo-Swissimage.png" alt="Map Preview" width="256" height="256"/></a><br/>Swisstopo - Swissimage</td>
+<td><a href="maps/Swisstopo-Swissimage.xml" download><img src="tiles/Swisstopo-Swissimage.jpg" alt="Map Preview" width="256" height="256"/></a><br/>Swisstopo - Swissimage</td>
 </tr>
 </table>
 <h3>United Kingdom (Great Britain)</h3>
diff --git a/tiles/Swisstopo-25k.png b/tiles/Swisstopo-25k.jpg
similarity index 100%
rename from tiles/Swisstopo-25k.png
rename to tiles/Swisstopo-25k.jpg
diff --git a/tiles/Swisstopo-Landeskarte.png b/tiles/Swisstopo-Landeskarte.jpg
similarity index 100%
rename from tiles/Swisstopo-Landeskarte.png
rename to tiles/Swisstopo-Landeskarte.jpg
diff --git a/tiles/Swisstopo-Swissimage.png b/tiles/Swisstopo-Swissimage.jpg
similarity index 100%
rename from tiles/Swisstopo-Swissimage.png
rename to tiles/Swisstopo-Swissimage.jpg