diff --git a/book/impls/10_minimum_example/060_template_compiler2/examples/playground/src/main.ts b/book/impls/10_minimum_example/060_template_compiler2/examples/playground/src/main.ts
index 02204715..76bcb090 100644
--- a/book/impls/10_minimum_example/060_template_compiler2/examples/playground/src/main.ts
+++ b/book/impls/10_minimum_example/060_template_compiler2/examples/playground/src/main.ts
@@ -7,6 +7,7 @@ const app = createApp({
       <img
         width="150px"
         src="https://upload.wikimedia.org/wikipedia/commons/thumb/9/95/Vue.js_Logo_2.svg/1200px-Vue.js_Logo_2.svg.png"
+        alt="Vue.js Logo"
       />
       <p><b>chibivue</b> is the minimal Vue.js</p>
 
diff --git a/book/impls/10_minimum_example/060_template_compiler3/examples/playground/src/main.ts b/book/impls/10_minimum_example/060_template_compiler3/examples/playground/src/main.ts
index b3b553cd..73b2fc2a 100644
--- a/book/impls/10_minimum_example/060_template_compiler3/examples/playground/src/main.ts
+++ b/book/impls/10_minimum_example/060_template_compiler3/examples/playground/src/main.ts
@@ -21,6 +21,7 @@ const app = createApp({
       <img
         width="150px"
         src="https://upload.wikimedia.org/wikipedia/commons/thumb/9/95/Vue.js_Logo_2.svg/1200px-Vue.js_Logo_2.svg.png"
+        alt="Vue.js Logo"
       />
       <p><b>chibivue</b> is the minimal Vue.js</p>
 
diff --git a/book/impls/10_minimum_example/070_sfc_compiler/examples/playground/src/main.ts b/book/impls/10_minimum_example/070_sfc_compiler/examples/playground/src/main.ts
index b3b553cd..73b2fc2a 100644
--- a/book/impls/10_minimum_example/070_sfc_compiler/examples/playground/src/main.ts
+++ b/book/impls/10_minimum_example/070_sfc_compiler/examples/playground/src/main.ts
@@ -21,6 +21,7 @@ const app = createApp({
       <img
         width="150px"
         src="https://upload.wikimedia.org/wikipedia/commons/thumb/9/95/Vue.js_Logo_2.svg/1200px-Vue.js_Logo_2.svg.png"
+        alt="Vue.js Logo"
       />
       <p><b>chibivue</b> is the minimal Vue.js</p>
 
diff --git a/book/impls/10_minimum_example/070_sfc_compiler2/examples/playground/src/App.vue b/book/impls/10_minimum_example/070_sfc_compiler2/examples/playground/src/App.vue
index f3c43551..62f680ea 100644
--- a/book/impls/10_minimum_example/070_sfc_compiler2/examples/playground/src/App.vue
+++ b/book/impls/10_minimum_example/070_sfc_compiler2/examples/playground/src/App.vue
@@ -24,6 +24,7 @@ export default {
     <img
       width="150px"
       src="https://upload.wikimedia.org/wikipedia/commons/thumb/9/95/Vue.js_Logo_2.svg/1200px-Vue.js_Logo_2.svg.png"
+      alt="Vue.js Logo"
     />
     <p><b>chibivue</b> is the minimal Vue.js</p>
 
diff --git a/book/impls/10_minimum_example/070_sfc_compiler3/examples/playground/src/App.vue b/book/impls/10_minimum_example/070_sfc_compiler3/examples/playground/src/App.vue
index f3c43551..62f680ea 100644
--- a/book/impls/10_minimum_example/070_sfc_compiler3/examples/playground/src/App.vue
+++ b/book/impls/10_minimum_example/070_sfc_compiler3/examples/playground/src/App.vue
@@ -24,6 +24,7 @@ export default {
     <img
       width="150px"
       src="https://upload.wikimedia.org/wikipedia/commons/thumb/9/95/Vue.js_Logo_2.svg/1200px-Vue.js_Logo_2.svg.png"
+      alt="Vue.js Logo"
     />
     <p><b>chibivue</b> is the minimal Vue.js</p>
 
diff --git a/book/impls/10_minimum_example/070_sfc_compiler4/examples/playground/src/App.vue b/book/impls/10_minimum_example/070_sfc_compiler4/examples/playground/src/App.vue
index f3c43551..62f680ea 100644
--- a/book/impls/10_minimum_example/070_sfc_compiler4/examples/playground/src/App.vue
+++ b/book/impls/10_minimum_example/070_sfc_compiler4/examples/playground/src/App.vue
@@ -24,6 +24,7 @@ export default {
     <img
       width="150px"
       src="https://upload.wikimedia.org/wikipedia/commons/thumb/9/95/Vue.js_Logo_2.svg/1200px-Vue.js_Logo_2.svg.png"
+      alt="Vue.js Logo"
     />
     <p><b>chibivue</b> is the minimal Vue.js</p>
 
diff --git a/book/impls/30_basic_reactivity_system/010_ref/examples/playground/src/App.vue b/book/impls/30_basic_reactivity_system/010_ref/examples/playground/src/App.vue
index f3c43551..62f680ea 100644
--- a/book/impls/30_basic_reactivity_system/010_ref/examples/playground/src/App.vue
+++ b/book/impls/30_basic_reactivity_system/010_ref/examples/playground/src/App.vue
@@ -24,6 +24,7 @@ export default {
     <img
       width="150px"
       src="https://upload.wikimedia.org/wikipedia/commons/thumb/9/95/Vue.js_Logo_2.svg/1200px-Vue.js_Logo_2.svg.png"
+      alt="Vue.js Logo"
     />
     <p><b>chibivue</b> is the minimal Vue.js</p>
 
diff --git a/book/impls/30_basic_reactivity_system/020_shallow_ref/examples/playground/src/App.vue b/book/impls/30_basic_reactivity_system/020_shallow_ref/examples/playground/src/App.vue
index f3c43551..62f680ea 100644
--- a/book/impls/30_basic_reactivity_system/020_shallow_ref/examples/playground/src/App.vue
+++ b/book/impls/30_basic_reactivity_system/020_shallow_ref/examples/playground/src/App.vue
@@ -24,6 +24,7 @@ export default {
     <img
       width="150px"
       src="https://upload.wikimedia.org/wikipedia/commons/thumb/9/95/Vue.js_Logo_2.svg/1200px-Vue.js_Logo_2.svg.png"
+      alt="Vue.js Logo"
     />
     <p><b>chibivue</b> is the minimal Vue.js</p>
 
diff --git a/book/impls/30_basic_reactivity_system/030_to_ref/examples/playground/src/App.vue b/book/impls/30_basic_reactivity_system/030_to_ref/examples/playground/src/App.vue
index f3c43551..62f680ea 100644
--- a/book/impls/30_basic_reactivity_system/030_to_ref/examples/playground/src/App.vue
+++ b/book/impls/30_basic_reactivity_system/030_to_ref/examples/playground/src/App.vue
@@ -24,6 +24,7 @@ export default {
     <img
       width="150px"
       src="https://upload.wikimedia.org/wikipedia/commons/thumb/9/95/Vue.js_Logo_2.svg/1200px-Vue.js_Logo_2.svg.png"
+      alt="Vue.js Logo"
     />
     <p><b>chibivue</b> is the minimal Vue.js</p>
 
diff --git a/book/impls/30_basic_reactivity_system/040_to_refs/examples/playground/src/App.vue b/book/impls/30_basic_reactivity_system/040_to_refs/examples/playground/src/App.vue
index f3c43551..62f680ea 100644
--- a/book/impls/30_basic_reactivity_system/040_to_refs/examples/playground/src/App.vue
+++ b/book/impls/30_basic_reactivity_system/040_to_refs/examples/playground/src/App.vue
@@ -24,6 +24,7 @@ export default {
     <img
       width="150px"
       src="https://upload.wikimedia.org/wikipedia/commons/thumb/9/95/Vue.js_Logo_2.svg/1200px-Vue.js_Logo_2.svg.png"
+      alt="Vue.js Logo"
     />
     <p><b>chibivue</b> is the minimal Vue.js</p>
 
diff --git a/book/impls/30_basic_reactivity_system/050_computed/examples/playground/src/App.vue b/book/impls/30_basic_reactivity_system/050_computed/examples/playground/src/App.vue
index f3c43551..62f680ea 100644
--- a/book/impls/30_basic_reactivity_system/050_computed/examples/playground/src/App.vue
+++ b/book/impls/30_basic_reactivity_system/050_computed/examples/playground/src/App.vue
@@ -24,6 +24,7 @@ export default {
     <img
       width="150px"
       src="https://upload.wikimedia.org/wikipedia/commons/thumb/9/95/Vue.js_Logo_2.svg/1200px-Vue.js_Logo_2.svg.png"
+      alt="Vue.js Logo"
     />
     <p><b>chibivue</b> is the minimal Vue.js</p>
 
diff --git a/book/impls/30_basic_reactivity_system/060_computed_setter/examples/playground/src/App.vue b/book/impls/30_basic_reactivity_system/060_computed_setter/examples/playground/src/App.vue
index f3c43551..62f680ea 100644
--- a/book/impls/30_basic_reactivity_system/060_computed_setter/examples/playground/src/App.vue
+++ b/book/impls/30_basic_reactivity_system/060_computed_setter/examples/playground/src/App.vue
@@ -24,6 +24,7 @@ export default {
     <img
       width="150px"
       src="https://upload.wikimedia.org/wikipedia/commons/thumb/9/95/Vue.js_Logo_2.svg/1200px-Vue.js_Logo_2.svg.png"
+      alt="Vue.js Logo"
     />
     <p><b>chibivue</b> is the minimal Vue.js</p>
 
diff --git a/book/impls/30_basic_reactivity_system/070_watch/examples/playground/src/App.vue b/book/impls/30_basic_reactivity_system/070_watch/examples/playground/src/App.vue
index f3c43551..62f680ea 100644
--- a/book/impls/30_basic_reactivity_system/070_watch/examples/playground/src/App.vue
+++ b/book/impls/30_basic_reactivity_system/070_watch/examples/playground/src/App.vue
@@ -24,6 +24,7 @@ export default {
     <img
       width="150px"
       src="https://upload.wikimedia.org/wikipedia/commons/thumb/9/95/Vue.js_Logo_2.svg/1200px-Vue.js_Logo_2.svg.png"
+      alt="Vue.js Logo"
     />
     <p><b>chibivue</b> is the minimal Vue.js</p>
 
diff --git a/book/impls/30_basic_reactivity_system/080_watch_api_extends/examples/playground/src/App.vue b/book/impls/30_basic_reactivity_system/080_watch_api_extends/examples/playground/src/App.vue
index f3c43551..62f680ea 100644
--- a/book/impls/30_basic_reactivity_system/080_watch_api_extends/examples/playground/src/App.vue
+++ b/book/impls/30_basic_reactivity_system/080_watch_api_extends/examples/playground/src/App.vue
@@ -24,6 +24,7 @@ export default {
     <img
       width="150px"
       src="https://upload.wikimedia.org/wikipedia/commons/thumb/9/95/Vue.js_Logo_2.svg/1200px-Vue.js_Logo_2.svg.png"
+      alt="Vue.js Logo"
     />
     <p><b>chibivue</b> is the minimal Vue.js</p>
 
diff --git a/book/impls/30_basic_reactivity_system/090_watch_effect/examples/playground/src/App.vue b/book/impls/30_basic_reactivity_system/090_watch_effect/examples/playground/src/App.vue
index f3c43551..62f680ea 100644
--- a/book/impls/30_basic_reactivity_system/090_watch_effect/examples/playground/src/App.vue
+++ b/book/impls/30_basic_reactivity_system/090_watch_effect/examples/playground/src/App.vue
@@ -24,6 +24,7 @@ export default {
     <img
       width="150px"
       src="https://upload.wikimedia.org/wikipedia/commons/thumb/9/95/Vue.js_Logo_2.svg/1200px-Vue.js_Logo_2.svg.png"
+      alt="Vue.js Logo"
     />
     <p><b>chibivue</b> is the minimal Vue.js</p>
 
diff --git a/book/impls/30_basic_reactivity_system/100_reactive_proxy_target_type/examples/playground/src/App.vue b/book/impls/30_basic_reactivity_system/100_reactive_proxy_target_type/examples/playground/src/App.vue
index f3c43551..62f680ea 100644
--- a/book/impls/30_basic_reactivity_system/100_reactive_proxy_target_type/examples/playground/src/App.vue
+++ b/book/impls/30_basic_reactivity_system/100_reactive_proxy_target_type/examples/playground/src/App.vue
@@ -24,6 +24,7 @@ export default {
     <img
       width="150px"
       src="https://upload.wikimedia.org/wikipedia/commons/thumb/9/95/Vue.js_Logo_2.svg/1200px-Vue.js_Logo_2.svg.png"
+      alt="Vue.js Logo"
     />
     <p><b>chibivue</b> is the minimal Vue.js</p>
 
diff --git a/book/impls/30_basic_reactivity_system/110_template_refs/examples/playground/src/App.vue b/book/impls/30_basic_reactivity_system/110_template_refs/examples/playground/src/App.vue
index f3c43551..62f680ea 100644
--- a/book/impls/30_basic_reactivity_system/110_template_refs/examples/playground/src/App.vue
+++ b/book/impls/30_basic_reactivity_system/110_template_refs/examples/playground/src/App.vue
@@ -24,6 +24,7 @@ export default {
     <img
       width="150px"
       src="https://upload.wikimedia.org/wikipedia/commons/thumb/9/95/Vue.js_Logo_2.svg/1200px-Vue.js_Logo_2.svg.png"
+      alt="Vue.js Logo"
     />
     <p><b>chibivue</b> is the minimal Vue.js</p>
 
diff --git a/book/impls/30_basic_reactivity_system/120_proxy_handler_improvement/examples/playground/src/App.vue b/book/impls/30_basic_reactivity_system/120_proxy_handler_improvement/examples/playground/src/App.vue
index f3c43551..62f680ea 100644
--- a/book/impls/30_basic_reactivity_system/120_proxy_handler_improvement/examples/playground/src/App.vue
+++ b/book/impls/30_basic_reactivity_system/120_proxy_handler_improvement/examples/playground/src/App.vue
@@ -24,6 +24,7 @@ export default {
     <img
       width="150px"
       src="https://upload.wikimedia.org/wikipedia/commons/thumb/9/95/Vue.js_Logo_2.svg/1200px-Vue.js_Logo_2.svg.png"
+      alt="Vue.js Logo"
     />
     <p><b>chibivue</b> is the minimal Vue.js</p>
 
diff --git a/book/online-book/src/10-minimum-example/070-more-complex-parser.md b/book/online-book/src/10-minimum-example/070-more-complex-parser.md
index 9a92d45d..d1d50bba 100644
--- a/book/online-book/src/10-minimum-example/070-more-complex-parser.md
+++ b/book/online-book/src/10-minimum-example/070-more-complex-parser.md
@@ -14,6 +14,7 @@ const app = createApp({
       <img
         width="150px"
         src="https://upload.wikimedia.org/wikipedia/commons/thumb/9/95/Vue.js_Logo_2.svg/1200px-Vue.js_Logo_2.svg.png"
+        alt="Vue.js Logo"
       />
       <p><b>chibivue</b> is the minimal Vue.js</p>
 
@@ -566,6 +567,7 @@ const app = createApp({
       <img
         width="150px"
         src="https://upload.wikimedia.org/wikipedia/commons/thumb/9/95/Vue.js_Logo_2.svg/1200px-Vue.js_Logo_2.svg.png"
+        alt="Vue.js Logo"
       />
       <p><b>chibivue</b> is the minimal Vue.js</p>
 
@@ -673,6 +675,7 @@ const app = createApp({
       <img
         width="150px"
         src="https://upload.wikimedia.org/wikipedia/commons/thumb/9/95/Vue.js_Logo_2.svg/1200px-Vue.js_Logo_2.svg.png"
+        alt="Vue.js Logo"
       />
       <p><b>chibivue</b> is the minimal Vue.js</p>
 
@@ -733,6 +736,7 @@ const app = createApp({
       <img
         width="150px"
         src="https://upload.wikimedia.org/wikipedia/commons/thumb/9/95/Vue.js_Logo_2.svg/1200px-Vue.js_Logo_2.svg.png"
+        alt="Vue.js Logo"
       />
       <p><b>chibivue</b> is the minimal Vue.js</p>
 
diff --git a/book/online-book/src/10-minimum-example/080-template-binding.md b/book/online-book/src/10-minimum-example/080-template-binding.md
index 5091883d..34ba6876 100644
--- a/book/online-book/src/10-minimum-example/080-template-binding.md
+++ b/book/online-book/src/10-minimum-example/080-template-binding.md
@@ -25,6 +25,7 @@ const app = createApp({
       <img
         width="150px"
         src="https://upload.wikimedia.org/wikipedia/commons/thumb/9/95/Vue.js_Logo_2.svg/1200px.js_Logo_2.svg.png"
+        alt="Vue.js Logo"
       />
       <p><b>chibivue</b> is the minimal Vue.js</p>
 
@@ -368,6 +369,7 @@ const app = createApp({
       <img
         width="150px"
         src="https://upload.wikimedia.org/wikipedia/commons/thumb/9/95/Vue.js_Logo_2.svg/1200px.js_Logo_2.svg.png"
+        alt="Vue.js Logo"
       />
       <p><b>chibivue</b> is the minimal Vue.js</p>
 
@@ -505,6 +507,7 @@ const app = createApp({
       <img
         width="150px"
         src="https://upload.wikimedia.org/wikipedia/commons/thumb/9/95/Vue.js_Logo_2.svg/1200px.js_Logo_2.svg.png"
+        alt="Vue.js Logo"
       />
       <p><b>chibivue</b> is the minimal Vue.js</p>
 
@@ -662,6 +665,7 @@ const app = createApp({
       <img
         width="150px"
         src="https://upload.wikimedia.org/wikipedia/commons/thumb/9/95/Vue.js_Logo_2.svg/1200px.js_Logo_2.svg.png"
+        alt="Vue.js Logo"
       />
       <p><b>chibivue</b> is the minimal Vue.js</p>
 
diff --git a/book/online-book/src/10-minimum-example/090-minimum-sfc.md b/book/online-book/src/10-minimum-example/090-minimum-sfc.md
index 6eb18da7..c116aa40 100644
--- a/book/online-book/src/10-minimum-example/090-minimum-sfc.md
+++ b/book/online-book/src/10-minimum-example/090-minimum-sfc.md
@@ -30,6 +30,7 @@ export default {
     <img
       width="150px"
       src="https://upload.wikimedia.org/wikipedia/commons/thumb/9/95/Vue.js_Logo_2.svg/1200px-Vue.js_Logo_2.svg.png"
+      alt="Vue.js Logo"
     />
     <p><b>chibivue</b> is the minimal Vue.js</p>
 
@@ -285,6 +286,7 @@ export default {
     <img
       width="150px"
       src="https://upload.wikimedia.org/wikipedia/commons/thumb/9/95/Vue.js_Logo_2.svg/1200px-Vue.js_Logo_2.svg.png"
+      alt="Vue.js Logo"
     />
     <p><b>chibivue</b> is the minimal Vue.js</p>
 
diff --git a/book/online-book/src/10-minimum-example/100-break.md b/book/online-book/src/10-minimum-example/100-break.md
index 73b36190..64f23306 100644
--- a/book/online-book/src/10-minimum-example/100-break.md
+++ b/book/online-book/src/10-minimum-example/100-break.md
@@ -220,6 +220,7 @@ const app = createApp({
       <img
         width="150px"
         src="https://upload.wikimedia.org/wikipedia/commons/thumb/9/95/Vue.js_Logo_2.svg/1200px-Vue.js_Logo_2.svg.png"
+        alt="Vue.js Logo"
       />
       <p><b>chibivue</b> is the minimal Vue.js</p>
 
@@ -275,6 +276,7 @@ export default {
     <img
       width="150px"
       src="https://upload.wikimedia.org/wikipedia/commons/thumb/9/95/Vue.js_Logo_2.svg/1200px-Vue.js_Logo_2.svg.png"
+      alt="Vue.js Logo"
     />
     <p><b>chibivue</b> is the minimal Vue.js</p>
 
diff --git a/book/online-book/src/en/00-introduction/010-about.md b/book/online-book/src/en/00-introduction/010-about.md
index 45beae23..71271a2c 100644
--- a/book/online-book/src/en/00-introduction/010-about.md
+++ b/book/online-book/src/en/00-introduction/010-about.md
@@ -94,6 +94,7 @@ Since this book has turned out quite voluminous, I've set achievement milestones
       <img
         width="150px"
         src="https://upload.wikimedia.org/wikipedia/commons/thumb/9/95/Vue.js_Logo_2.svg/1200px-Vue.js_Logo_2.svg.png"
+        alt="Vue.js Logo"
       />
       <p><b>chibivue</b> is the minimal Vue.js</p>
 
diff --git a/book/online-book/src/en/10-minimum-example/070-more-complex-parser.md b/book/online-book/src/en/10-minimum-example/070-more-complex-parser.md
index 383a3295..5751c71f 100644
--- a/book/online-book/src/en/10-minimum-example/070-more-complex-parser.md
+++ b/book/online-book/src/en/10-minimum-example/070-more-complex-parser.md
@@ -14,6 +14,7 @@ const app = createApp({
       <img
         width="150px"
         src="https://upload.wikimedia.org/wikipedia/commons/thumb/9/95/Vue.js_Logo_2.svg/1200px-Vue.js_Logo_2.svg.png"
+        alt="Vue.js Logo"
       />
       <p><b>chibivue</b> is the minimal Vue.js</p>
 
@@ -566,6 +567,7 @@ const app = createApp({
       <img
         width="150px"
         src="https://upload.wikimedia.org/wikipedia/commons/thumb/9/95/Vue.js_Logo_2.svg/1200px-Vue.js_Logo_2.svg.png"
+        alt="Vue.js Logo"
       />
       <p><b>chibivue</b> is the minimal Vue.js</p>
 
@@ -673,6 +675,7 @@ const app = createApp({
       <img
         width="150px"
         src="https://upload.wikimedia.org/wikipedia/commons/thumb/9/95/Vue.js_Logo_2.svg/1200px-Vue.js_Logo_2.svg.png"
+        alt="Vue.js Logo"
       />
       <p><b>chibivue</b> is the minimal Vue.js</p>
 
@@ -734,6 +737,7 @@ const app = createApp({
       <img
         width="150px"
         src="https://upload.wikimedia.org/wikipedia/commons/thumb/9/95/Vue.js_Logo_2.svg/1200px-Vue.js_Logo_2.svg.png"
+        alt="Vue.js Logo"
       />
       <p><b>chibivue</b> is the minimal Vue.js</p>
 
diff --git a/book/online-book/src/en/10-minimum-example/080-template-binding.md b/book/online-book/src/en/10-minimum-example/080-template-binding.md
index c62275bc..c5db69cf 100644
--- a/book/online-book/src/en/10-minimum-example/080-template-binding.md
+++ b/book/online-book/src/en/10-minimum-example/080-template-binding.md
@@ -362,6 +362,7 @@ const app = createApp({
       <img
         width="150px"
         src="https://upload.wikimedia.org/wikipedia/commons/thumb/9/95/Vue.js_Logo_2.svg/1200px.js_Logo_2.svg.png"
+        alt="Vue.js Logo"
       />
       <p><b>chibivue</b> is the minimal Vue.js</p>
 
@@ -499,6 +500,7 @@ const app = createApp({
       <img
         width="150px"
         src="https://upload.wikimedia.org/wikipedia/commons/thumb/9/95/Vue.js_Logo_2.svg/1200px.js_Logo_2.svg.png"
+        alt="Vue.js Logo"
       />
       <p><b>chibivue</b> is the minimal Vue.js</p>
 
@@ -656,6 +658,7 @@ const app = createApp({
       <img
         width="150px"
         src="https://upload.wikimedia.org/wikipedia/commons/thumb/9/95/Vue.js_Logo_2.svg/1200px.js_Logo_2.svg.png"
+        alt="Vue.js Logo"
       />
       <p><b>chibivue</b> is the minimal Vue.js</p>
 
diff --git a/book/online-book/src/en/10-minimum-example/090-minimum-sfc.md b/book/online-book/src/en/10-minimum-example/090-minimum-sfc.md
index 21ce18db..5fa195e7 100644
--- a/book/online-book/src/en/10-minimum-example/090-minimum-sfc.md
+++ b/book/online-book/src/en/10-minimum-example/090-minimum-sfc.md
@@ -30,6 +30,7 @@ export default {
     <img
       width="150px"
       src="https://upload.wikimedia.org/wikipedia/commons/thumb/9/95/Vue.js_Logo_2.svg/1200px-Vue.js_Logo_2.svg.png"
+      alt="Vue.js Logo"
     />
     <p><b>chibivue</b> is the minimal Vue.js</p>
 
@@ -284,6 +285,7 @@ export default {
     <img
       width="150px"
       src="https://upload.wikimedia.org/wikipedia/commons/thumb/9/95/Vue.js_Logo_2.svg/1200px-Vue.js_Logo_2.svg.png"
+      alt="Vue.js Logo"
     />
     <p><b>chibivue</b> is the minimal Vue.js</p>
 
diff --git a/book/online-book/src/en/10-minimum-example/100-break.md b/book/online-book/src/en/10-minimum-example/100-break.md
index d3c9395c..bf0e3670 100644
--- a/book/online-book/src/en/10-minimum-example/100-break.md
+++ b/book/online-book/src/en/10-minimum-example/100-break.md
@@ -216,6 +216,7 @@ const app = createApp({
       <img
         width="150px"
         src="https://upload.wikimedia.org/wikipedia/commons/thumb/9/95/Vue.js_Logo_2.svg/1200px-Vue.js_Logo_2.svg.png"
+        alt="Vue.js Logo"
       />
       <p><b>chibivue</b> is the minimal Vue.js</p>
 
@@ -270,6 +271,7 @@ export default {
     <img
       width="150px"
       src="https://upload.wikimedia.org/wikipedia/commons/thumb/9/95/Vue.js_Logo_2.svg/1200px-Vue.js_Logo_2.svg.png"
+      alt="Vue.js Logo"
     />
     <p><b>chibivue</b> is the minimal Vue.js</p>