diff --git a/layouts/partials/article-preview.html b/layouts/partials/article-preview.html
index e1dc069..08f602d 100644
--- a/layouts/partials/article-preview.html
+++ b/layouts/partials/article-preview.html
@@ -1,7 +1,7 @@
 {{ $isBig := default false (.Scratch.Get "big") }}
 {{ $title := .RenderString .Title }}
 {{ $titleWithoutHTML := $title | plainify }}
-{{ $pictureSize := cond $isBig "220x220 Center" "100x100 Center" }}
+{{ $pictureSize := cond $isBig "220x220 Center webp" "100x100 Center webp" }}
 {{ $truncateSize := cond $isBig 180 90}}
 <div class="post{{ if $isBig }} big{{ end }}">
   <div class="picture">
diff --git a/layouts/partials/conseilmunicipal.html b/layouts/partials/conseilmunicipal.html
index 3a0cc40..1ed611d 100644
--- a/layouts/partials/conseilmunicipal.html
+++ b/layouts/partials/conseilmunicipal.html
@@ -3,7 +3,7 @@
 <div class="container conseilmunicipal">
 {{ range sort $.Site.Data.conseilmunicipal.conseilmunicipal "nom" }}
   {{ $image := $headless.Resources.GetMatch .image }}
-  {{ $resized := $image.Resize "250x" }}
+  {{ $resized := $image.Resize "250x webp" }}
   {{ partial "person.html" (merge . (dict "image" $resized.RelPermalink)) }}
 {{ end }}
 </div>
diff --git a/layouts/partials/header.html b/layouts/partials/header.html
index ebac301..55b0987 100644
--- a/layouts/partials/header.html
+++ b/layouts/partials/header.html
@@ -1,6 +1,6 @@
 {{ $isBig := (default .IsHome .Params.big) }}
-{{ $imageSizeSmall := cond $isBig "600x600 Top" "600x400 Center" }}
-{{ $imageSizeBig := cond $isBig "1920x850 Top" "1920x450 Center" }}
+{{ $imageSizeSmall := cond $isBig "600x600 Top webp" "600x400 Center webp" }}
+{{ $imageSizeBig := cond $isBig "1920x850 Top webp" "1920x450 Center webp" }}
 <header class="header{{ if $isBig }} home{{ end }}">
   {{ $headless := .Site.GetPage "/" }}
   {{ $image := default ($headless.Resources.GetMatch "**.jpg") (.Resources.GetMatch (default "**.jpg" .Params.image)) }}
diff --git a/layouts/partials/maire.html b/layouts/partials/maire.html
index dc72f57..09acca2 100644
--- a/layouts/partials/maire.html
+++ b/layouts/partials/maire.html
@@ -1,6 +1,6 @@
 {{ $headless := .Site.GetPage "/viemunicipale/lemotdumaire" }}
 <p class="maire">
   {{ $image := $headless.Resources.GetMatch "maire.jpg" }}
-  {{ $resized := $image.Resize "300x" }}
+  {{ $resized := $image.Resize "300x webp" }}
   <img class="round" src="{{ $resized.RelPermalink }}" alt="Didier PONCET" />
 </p>