diff --git a/README.md b/README.md
index 2cc43bf..45f9e51 100644
--- a/README.md
+++ b/README.md
@@ -13,7 +13,11 @@ native Layer-4 sockets (TCP, UDP, ICMP/ICMPv6 echo) on a host. It doesn't
 require any capabilities or privileges, and it can be used as a simple
 replacement for Slirp.
 
-<img src="/builds/latest/web/passt_overview.png" usemap="#image-map" class="bright" style="z-index: 20; position: relative;">
+<picture>
+  <source type="image/webp" srcset="/builds/latest/web/passt_overview.webp">
+  <source type="image/png" srcset="/builds/latest/web/passt_overview.png">
+  <img src="/builds/latest/web/passt_overview.png" usemap="#image-map" class="bright" style="z-index: 20; position: relative;" alt="Overview diagram of passt">
+</picture>
 <map name="image-map" id="map_overview">
     <area class="map_area" target="_blank" href="https://man7.org/linux/man-pages/man7/tcp.7.html" coords="229,275,246,320,306,294,287,249" shape="poly">
     <area class="map_area" target="_blank" href="https://lwn.net/Articles/420799/" coords="230,201,243,246,297,232,289,186" shape="poly">
@@ -112,7 +116,11 @@ destination address are moved directly between Layer-4 sockets, avoiding Layer-2
 translations, using the _splice_(2) and _recvmmsg_(2)/_sendmmsg_(2) system calls
 for TCP and UDP, respectively.
 
-<img src="/builds/latest/web/pasta_overview.png" class="bright" style="z-index: 20; position: relative;">
+<picture>
+  <source type="image/webp" srcset="/builds/latest/web/pasta_overview.webp">
+  <source type="image/png" srcset="/builds/latest/web/pasta_overview.png">
+  <img src="/builds/latest/web/passt_overview.png" class="bright" style="z-index: 20; position: relative;" alt="Overview diagram of pasta">
+</picture>
 
 - [Motivation](#motivation)
 - [Features](#features)
diff --git a/hooks/pre-push b/hooks/pre-push
index b75fe4b..73dac94 100755
--- a/hooks/pre-push
+++ b/hooks/pre-push
@@ -34,9 +34,9 @@ ssh "${USER_HOST}" 				"mkdir -p ${WEB} ${TEST} ${BIN}"
 cd test
 
 ./ci
-scp perf.js ci.js ../doc/*.png			"${USER_HOST}:${WEB}/"
+gzip -fk9 perf.js ci.js
+scp perf.js perf.js.gz ci.js ci.js.gz		"${USER_HOST}:${WEB}/"
 scp test_logs/* 				"${USER_HOST}:${TEST}/"
-
 ./run_demo
 
 for cast in ci demo_pasta demo_podman demo_passt; do
@@ -58,6 +58,11 @@ scp *.deb *.rpm					"${USER_HOST}:${BIN}/"
 man2html -M "/" passt.1 > passt.1.html
 scp passt.1.html				"${USER_HOST}:${WEB}/"
 
+for pic in passt_overview pasta_overview; do
+	cwebp -preset drawing -q 10 "doc/${pic}.png" -o "doc/${pic}.webp"
+	scp "doc/${pic}.png" "doc/${pic}.png"	"${USER_HOST}:${WEB}/"
+done
+
 ssh "${USER_HOST}"				"mv ${LATEST} ${AWAY}"
 ssh "${USER_HOST}"				"mv ${TEMP} ${LATEST}"
 ssh "${USER_HOST}"				"rm -rf ${AWAY}"