diff --git a/public/templates/index.tmpl b/public/templates/index.tmpl
index 26b6942..f5f8c1b 100644
--- a/public/templates/index.tmpl
+++ b/public/templates/index.tmpl
@@ -78,7 +78,7 @@
           {{/if}}
           <div class="details">
             <h3>{{name}}</h3>
-            <p class="identifier">identifier: {{@key}}{{#if formatted_filesize}} | size: {{formatted_filesize}}{{/if}} | type: {{#is_vector}}vector{{/is_vector}}{{^is_vector}}raster{{/is_vector}} data</p>
+            <p class="identifier">identifier: {{@key}}{{#if formatted_filesize}} | size: {{formatted_filesize}}{{/if}} | type: {{#is_vector}}vector{{/is_vector}}{{^is_vector}}raster{{/is_vector}} data {{#if extension}} | ext: {{extension}}{{/if}}</p>
             <p class="services">
               services: <a href="{{public_url}}data/{{@key}}.json{{&../key_query}}">TileJSON</a>
               {{#if wmts_link}}
diff --git a/src/server.js b/src/server.js
index 88d026c..9ce115a 100644
--- a/src/server.js
+++ b/src/server.js
@@ -494,7 +494,9 @@ function start(opts) {
           size /= 1024;
         }
         data_.formatted_filesize = `${size.toFixed(2)} ${suffix}`;
+        data_.extension = tilejson.extension;
       }
+      if (tilejson.extension) {data_.extension = tilejson.extension;}
     }
     return {
       styles: Object.keys(styles).length ? styles : null,