diff --git a/themes/2026/layouts/_partials/asides/complementary-images.html b/themes/2026/layouts/_partials/asides/complementary-images.html
index 3a9ab37e..5be2e072 100644
--- a/themes/2026/layouts/_partials/asides/complementary-images.html
+++ b/themes/2026/layouts/_partials/asides/complementary-images.html
@@ -100,7 +100,7 @@
         {{- $title := default (printf "Image complémentaire : %s" $imageName) (index $data "title") -}}
         {{- $thumbnail := . -}}
         {{- if and (ne .MediaType.SubType "svg") (gt .Width 360) -}}
-          {{- $thumbnail = .Resize "360x" -}}
+          {{- $thumbnail = .Resize "360x webp q80" -}}
         {{- end -}}
       <li>
         <a href="{{ .RelPermalink }}" title="{{ $title }}">
diff --git a/themes/2026/layouts/_partials/card.html b/themes/2026/layouts/_partials/card.html
index 45f53555..6fbf5759 100644
--- a/themes/2026/layouts/_partials/card.html
+++ b/themes/2026/layouts/_partials/card.html
@@ -41,6 +41,8 @@
   {{- $thumbnailTransform = "900x506" -}}
 {{- end -}}
 
+{{- $thumbnailOptions := printf "%s webp q80" $thumbnailTransform -}}
+
 {{- $coverPath := $page.Params.cover -}}
 {{- $image := false -}}
 {{- if $coverPath -}}
@@ -109,7 +111,7 @@
     <a href="{{ $page.RelPermalink }}">
       <figure>
         {{- with $image -}}
-        {{- $resized := .Fill $thumbnailTransform -}}
+        {{- $resized := .Fill $thumbnailOptions -}}
         <img src="{{ $resized.RelPermalink }}" alt="Image de couverture pour {{ $page.Title }}" loading="lazy">
         {{- end -}}
       </figure>
@@ -125,7 +127,7 @@
   <a href="{{ $page.RelPermalink }}">
     <figure>
       {{- with $image -}}
-      {{- $resized := .Fill $thumbnailTransform -}}
+      {{- $resized := .Fill $thumbnailOptions -}}
       <img src="{{ $resized.RelPermalink }}" alt="Image de couverture pour {{ $page.Title }}" loading="lazy">
       {{- end -}}
     </figure>
diff --git a/themes/2026/layouts/_partials/oeuvres/l-anankeisme.html b/themes/2026/layouts/_partials/oeuvres/l-anankeisme.html
index 1e4af0bc..2158e220 100644
--- a/themes/2026/layouts/_partials/oeuvres/l-anankeisme.html
+++ b/themes/2026/layouts/_partials/oeuvres/l-anankeisme.html
@@ -4,7 +4,7 @@
       {{- $assetPath := "images/oeuvres/l-anankeisme.png" -}}
       {{- $source := resources.Get $assetPath -}}
       {{- if $source -}}
-      {{- $img := $source.Resize "320x" -}}
+      {{- $img := $source.Resize "320x webp q80" -}}
       <img src="{{ $img.RelPermalink }}" width="{{ $img.Width }}" height="{{ $img.Height }}" alt="Couverture de L'Anankéisme" loading="lazy">
       {{- end -}}
     </figure>
diff --git a/themes/2026/layouts/_partials/oeuvres/l-humain-cette-espece-primitive.html b/themes/2026/layouts/_partials/oeuvres/l-humain-cette-espece-primitive.html
index ca0bac8f..fc965e4c 100644
--- a/themes/2026/layouts/_partials/oeuvres/l-humain-cette-espece-primitive.html
+++ b/themes/2026/layouts/_partials/oeuvres/l-humain-cette-espece-primitive.html
@@ -4,7 +4,7 @@
       {{- $assetPath := "images/oeuvres/l-humain-cette-espece-primitive.jpeg" -}}
       {{- $source := resources.Get $assetPath -}}
       {{- if $source -}}
-      {{- $img := $source.Resize "320x" -}}
+      {{- $img := $source.Resize "320x webp q80" -}}
       <img src="{{ $img.RelPermalink }}" width="{{ $img.Width }}" height="{{ $img.Height }}" alt="Couverture de L'Humain, cette espèce primitive" loading="lazy">
       {{- end -}}
     </figure>
diff --git a/themes/2026/layouts/_partials/site-title.html b/themes/2026/layouts/_partials/site-title.html
index ae2683a7..e8717c48 100644
--- a/themes/2026/layouts/_partials/site-title.html
+++ b/themes/2026/layouts/_partials/site-title.html
@@ -6,7 +6,7 @@
 {{- $logo := resources.GetMatch $logoPath -}}
 <a href="{{ "/" | relURL }}" aria-label="Revenir à l'accueil">
   {{- with $logo -}}
-  {{- $resized := .Resize "64x" -}}
+  {{- $resized := .Resize "64x webp q80" -}}
   <img src="{{ $resized.RelPermalink }}" alt="">
   {{- end -}}
   <strong>{{ $site.Title }}</strong>
diff --git a/themes/2026/layouts/_partials/timeline-list.html b/themes/2026/layouts/_partials/timeline-list.html
index a6beb8bd..b8770f56 100644
--- a/themes/2026/layouts/_partials/timeline-list.html
+++ b/themes/2026/layouts/_partials/timeline-list.html
@@ -36,7 +36,7 @@
         {{- with $image -}}
         <a href="{{ $page.RelPermalink }}">
           <figure>
-            {{- $resized := .Fill "600x340" -}}
+            {{- $resized := .Fill "600x340 webp q80" -}}
             <img src="{{ $resized.RelPermalink }}" alt="Image de couverture pour {{ $page.Title }}" loading="lazy">
           </figure>
         </a>
diff --git a/themes/2026/layouts/home.html b/themes/2026/layouts/home.html
index de2243c3..f1145a53 100644
--- a/themes/2026/layouts/home.html
+++ b/themes/2026/layouts/home.html
@@ -305,7 +305,7 @@
           <a href="{{ $page.RelPermalink }}">
               <figure>
               {{- with $image -}}
-              {{- $resized := .Fill "166x91" -}}
+              {{- $resized := .Fill "166x91 webp q80" -}}
               <img src="{{ $resized.RelPermalink }}" alt="Capture du lien {{ $page.Title }}" loading="lazy">
               {{- end -}}
             </figure>
@@ -391,7 +391,7 @@
             <a href="{{ $item.RelPermalink }}" title="{{ $item.Title }}">
               <figure>
                 {{- with $itemImage -}}
-                {{- $resized := .Resize "x128" -}}
+                {{- $resized := .Resize "x128 webp q80" -}}
                 <img src="{{ $resized.RelPermalink }}" alt="{{ $item.Title }}" title="{{ $item.Title }}" loading="lazy">
                 {{- end -}}
               </figure>