diff --git a/public/templates/data.tmpl b/public/templates/data.tmpl
index be45540..9b7f14c 100644
--- a/public/templates/data.tmpl
+++ b/public/templates/data.tmpl
@@ -100,9 +100,10 @@
       version: 8,
       sources: {
         'RasterSource': {
-        type: 'raster',
-        url: '{{public_url}}data/{{id}}.json' + keyParam
-      }
+          type: 'raster',
+          url: '{{public_url}}data/{{id}}.json' + keyParam,
+          tileSize": 256
+        }
       },
       layers: [
         {
diff --git a/public/templates/viewer.tmpl b/public/templates/viewer.tmpl
index a90fd46..a25b18f 100644
--- a/public/templates/viewer.tmpl
+++ b/public/templates/viewer.tmpl
@@ -62,9 +62,10 @@
           version: 8,
           sources: {
             'RasterSource': {
-            type: 'raster',
-            url: '{{public_url}}styles/{{id}}.json' + keyParam
-          }
+              type: 'raster',
+              url: '{{public_url}}styles/{{id}}.json' + keyParam,
+              tileSize": 256
+            }
           },
           layers: [
             {