diff --git a/docker/demo/Dockerfile b/docker/demo/Dockerfile
index 77bd0678e..c18575b77 100644
--- a/docker/demo/Dockerfile
+++ b/docker/demo/Dockerfile
@@ -1,12 +1,17 @@
 FROM photoprism/photoprism:latest as build
 
-RUN mkdir -p /srv/photoprism/photos/import && \
-    wget -qO- https://dl.photoprism.org/fixtures/demo.tar.gz | tar xvz -C /srv/photoprism/photos/import
-
-RUN photoprism import
-
 # Hide TensorFlow warnings
 ENV TF_CPP_MIN_LOG_LEVEL 2
 
+RUN mkdir -p /srv/photoprism/photos/import && \
+    wget -qO- https://dl.photoprism.org/fixtures/demo.tar.gz | tar xvz -C /srv/photoprism/photos/import
+
+# Import example photos
+RUN photoprism import
+
+# Thumbnail cache warmup
+RUN photoprism thumbnails -q -s 50 -s 100 -s 320 -s 500
+RUN photoprism thumbnails -s 720 -s 1280 -s 1920 -s 2560 -s 3840
+
 # Start PhotoPrism server
 CMD photoprism start
diff --git a/docker/photoprism/Dockerfile b/docker/photoprism/Dockerfile
index f70e3357d..66b9f55ac 100644
--- a/docker/photoprism/Dockerfile
+++ b/docker/photoprism/Dockerfile
@@ -12,6 +12,9 @@ FROM ubuntu:18.04
 
 WORKDIR /srv/photoprism
 
+# Hide TensorFlow warnings
+ENV TF_CPP_MIN_LOG_LEVEL 2
+
 # Install additional distribution packages
 RUN apt-get update && apt-get install -y --no-install-recommends \
         curl \
@@ -45,9 +48,6 @@ RUN apt-get update && \
 # Show photoprism version
 RUN photoprism -v
 
-# Hide TensorFlow warnings
-ENV TF_CPP_MIN_LOG_LEVEL 2
-
 # Expose HTTP & TiDB port
 EXPOSE 80
 EXPOSE 4000
diff --git a/internal/commands/thumbnails.go b/internal/commands/thumbnails.go
index 2f0cac311..e356ac401 100644
--- a/internal/commands/thumbnails.go
+++ b/internal/commands/thumbnails.go
@@ -18,7 +18,7 @@ var ThumbnailsCommand = cli.Command{
 		},
 		cli.BoolFlag{
 			Name:  "default, d",
-			Usage: "Render default sizes: 320, 500, 640, 1280, 1920 and 2560px",
+			Usage: "Render default sizes: 720, 1280, 1920, 2560 and 3840px",
 		},
 		cli.BoolFlag{
 			Name:  "square, q",
@@ -40,7 +40,7 @@ func thumbnailsAction(ctx *cli.Context) error {
 	sizes := ctx.IntSlice("size")
 
 	if ctx.Bool("default") {
-		sizes = []int{320, 500, 640, 1280, 1920, 2560}
+		sizes = []int{720, 1280, 1920, 2560, 3840}
 	}
 
 	if len(sizes) == 0 {