diff --git a/build-windows.yaml b/build-windows.yaml
index 309d9bac23..146a9807c7 100644
--- a/build-windows.yaml
+++ b/build-windows.yaml
@@ -31,3 +31,20 @@ services:
         - ${DOCKERHUB_ORGANISATION}/${DOCKERHUB_REPO}:${JENKINS_VERSION}-jdk17-hotspot-${WINDOWS_FLAVOR}-${WINDOWS_VERSION}
         - ${DOCKERHUB_ORGANISATION}/${DOCKERHUB_REPO}:${JENKINS_VERSION}-${WINDOWS_FLAVOR}-${WINDOWS_VERSION}
         - ${DOCKERHUB_ORGANISATION}/${DOCKERHUB_REPO}${SEPARATOR_LTS_PREFIX}${WINDOWS_FLAVOR}-${WINDOWS_VERSION}
+  jdk21:
+    image: ${DOCKERHUB_ORGANISATION}/${DOCKERHUB_REPO}${SEPARATOR_LTS_PREFIX}jdk21-hotspot-${WINDOWS_FLAVOR}-${WINDOWS_VERSION}
+    build:
+      context: ./
+      dockerfile: ./windows/${WINDOWS_FLAVOR}/hotspot/Dockerfile
+      args:
+        COMMIT_SHA: ${COMMIT_SHA}
+        JAVA_HOME: "C:/openjdk-21"
+        JAVA_VERSION: "21.0.2_13"
+        JENKINS_SHA: ${JENKINS_SHA}
+        JENKINS_VERSION: ${JENKINS_VERSION}
+        TOOLS_WINDOWS_VERSION: ${TOOLS_WINDOWS_VERSION}
+        WINDOWS_VERSION: ${WINDOWS_VERSION}
+      tags:
+        - ${DOCKERHUB_ORGANISATION}/${DOCKERHUB_REPO}:${JENKINS_VERSION}-jdk21-hotspot-${WINDOWS_FLAVOR}-${WINDOWS_VERSION}
+        - ${DOCKERHUB_ORGANISATION}/${DOCKERHUB_REPO}:${JENKINS_VERSION}-${WINDOWS_FLAVOR}-${WINDOWS_VERSION}
+        - ${DOCKERHUB_ORGANISATION}/${DOCKERHUB_REPO}${SEPARATOR_LTS_PREFIX}${WINDOWS_FLAVOR}-${WINDOWS_VERSION}
diff --git a/tests/functions.Tests.ps1 b/tests/functions.Tests.ps1
index 441280835c..915aba478d 100644
--- a/tests/functions.Tests.ps1
+++ b/tests/functions.Tests.ps1
@@ -20,7 +20,8 @@ Describe "[functions > $global:TEST_TAG] build image" {
   }
 }
 
-Describe "[functions > $global:TEST_TAG] Check-VersionLessThan" {
+# Only test on Java 21, one JDK is enough to test all versions
+Describe "[functions > $global:TEST_TAG] Check-VersionLessThan" -Skip:(-not $global:TEST_TAG.StartsWith('jdk21-')) {
   It 'exit codes work' {
     docker run --rm $global:SUT_IMAGE "exit -1"
     $LastExitCode | Should -Be -1
@@ -72,7 +73,8 @@ Describe "[functions > $global:TEST_TAG] Check-VersionLessThan" {
   }
 }
 
-Describe "[functions > $global:TEST_TAG] Copy-ReferenceFile" {
+# Only test on Java 21, one JDK is enough to test all versions
+Describe "[functions > $global:TEST_TAG] Copy-ReferenceFile" -Skip:(-not $global:TEST_TAG.StartsWith('jdk21-')) {
   It 'build test image' {
     $exitCode, $stdout, $stderr = Build-DockerChild $global:SUT_IMAGE $PSScriptRoot/functions
     $exitCode | Should -Be 0
diff --git a/tests/plugins-cli.Tests.ps1 b/tests/plugins-cli.Tests.ps1
index 85656cf44b..5c760f87ef 100644
--- a/tests/plugins-cli.Tests.ps1
+++ b/tests/plugins-cli.Tests.ps1
@@ -28,7 +28,8 @@ Describe "[plugins-cli > $global:TEST_TAG] cleanup container" {
   }
 }
 
-Describe "[plugins-cli > $global:TEST_TAG] plugins are installed with jenkins-plugin-cli" {
+# Only test on Java 21, one JDK is enough to test all versions
+Describe "[plugins-cli > $global:TEST_TAG] plugins are installed with jenkins-plugin-cli" -Skip:(-not $global:TEST_TAG.StartsWith('jdk21-')) {
   It 'builds child image' {
     $exitCode, $stdout, $stderr = Build-DockerChild $global:SUT_IMAGE-plugins-cli $PSScriptRoot/plugins-cli
     $exitCode | Should -Be 0
@@ -62,7 +63,8 @@ Describe "[plugins-cli > $global:TEST_TAG] plugins are installed with jenkins-pl
   }
 }
 
-Describe "[plugins-cli > $global:TEST_TAG] plugins are installed with jenkins-plugin-cli with non-default REF" {
+# Only test on Java 21, one JDK is enough to test all versions
+Describe "[plugins-cli > $global:TEST_TAG] plugins are installed with jenkins-plugin-cli with non-default REF" -Skip:(-not $global:TEST_TAG.StartsWith('jdk21-')) {
   It 'builds child image' {
     $exitCode, $stdout, $stderr = Build-DockerChild $global:SUT_IMAGE-plugins-cli-ref $PSScriptRoot/plugins-cli/ref
     $exitCode | Should -Be 0
@@ -99,7 +101,8 @@ Describe "[plugins-cli > $global:TEST_TAG] plugins are installed with jenkins-pl
   }
 }
 
-Describe "[plugins-cli > $global:TEST_TAG] plugins are installed with jenkins-plugin-cli from a plugins file" {
+# Only test on Java 21, one JDK is enough to test all versions
+Describe "[plugins-cli > $global:TEST_TAG] plugins are installed with jenkins-plugin-cli from a plugins file" -Skip:(-not $global:TEST_TAG.StartsWith('jdk21-')) {
   It 'builds child image' {
     $exitCode, $stdout, $stderr = Build-DockerChild $global:SUT_IMAGE-plugins-cli $PSScriptRoot/plugins-cli
     $exitCode | Should -Be 0
@@ -136,7 +139,8 @@ Describe "[plugins-cli > $global:TEST_TAG] plugins are installed with jenkins-pl
   }
 }
 
-Describe "[plugins-cli > $global:TEST_TAG] plugins are installed with jenkins-plugin-cli even when already exist" {
+# Only test on Java 21, one JDK is enough to test all versions
+Describe "[plugins-cli > $global:TEST_TAG] plugins are installed with jenkins-plugin-cli even when already exist" -Skip:(-not $global:TEST_TAG.StartsWith('jdk21-')) {
   It 'builds child image' {
     $exitCode, $stdout, $stderr = Build-DockerChild $global:SUT_IMAGE-plugins-cli $PSScriptRoot/plugins-cli
     $exitCode | Should -Be 0
@@ -162,7 +166,8 @@ Describe "[plugins-cli > $global:TEST_TAG] clean work directory" {
   }
 }
 
-Describe "[plugins-cli > $global:TEST_TAG] plugins are getting upgraded but not downgraded" {
+# Only test on Java 21, one JDK is enough to test all versions
+Describe "[plugins-cli > $global:TEST_TAG] plugins are getting upgraded but not downgraded" -Skip:(-not $global:TEST_TAG.StartsWith('jdk21-')) {
   It 'builds child image' {
     # Initial execution
     $exitCode, $stdout, $stderr = Build-DockerChild $global:SUT_IMAGE-plugins-cli $PSScriptRoot/plugins-cli
@@ -212,7 +217,8 @@ Describe "[plugins-cli > $global:TEST_TAG] clean work directory" {
   }
 }
 
-Describe "[plugins-cli > $global:TEST_TAG] do not upgrade if plugin has been manually updated" {
+# Only test on Java 21, one JDK is enough to test all versions
+Describe "[plugins-cli > $global:TEST_TAG] do not upgrade if plugin has been manually updated" -Skip:(-not $global:TEST_TAG.StartsWith('jdk21-')) {
   
   It 'builds child image' {
     $exitCode, $stdout, $stderr = Build-DockerChild $global:SUT_IMAGE-plugins-cli $PSScriptRoot/plugins-cli
@@ -261,7 +267,8 @@ Describe "[plugins-cli > $global:TEST_TAG] clean work directory" {
   }
 }
 
-Describe "[plugins-cli > $global:TEST_TAG] upgrade plugin even if it has been manually updated when PLUGINS_FORCE_UPGRADE=true" {
+# Only test on Java 21, one JDK is enough to test all versions
+Describe "[plugins-cli > $global:TEST_TAG] upgrade plugin even if it has been manually updated when PLUGINS_FORCE_UPGRADE=true" -Skip:(-not $global:TEST_TAG.StartsWith('jdk21-')) {
   It 'builds child image' {
     $exitCode, $stdout, $stderr = Build-DockerChild $global:SUT_IMAGE-plugins-cli $PSScriptRoot/plugins-cli
     $exitCode | Should -Be 0
@@ -307,14 +314,16 @@ Describe "[plugins-cli > $global:TEST_TAG] clean work directory" {
   }
 }
 
-Describe "[plugins-cli > $global:TEST_TAG] plugins are installed with jenkins-plugin-cli and no war" {
+# Only test on Java 21, one JDK is enough to test all versions
+Describe "[plugins-cli > $global:TEST_TAG] plugins are installed with jenkins-plugin-cli and no war" -Skip:(-not $global:TEST_TAG.StartsWith('jdk21-')) {
   It 'builds child image' {
     $exitCode, $stdout, $stderr = Build-DockerChild $global:SUT_IMAGE-plugins-cli-no-war $PSScriptRoot/plugins-cli/no-war
     $exitCode | Should -Be 0
   }
 }
 
-Describe "[plugins-cli > $global:TEST_TAG] Use a custom jenkins.war" {
+# Only test on Java 21, one JDK is enough to test all versions
+Describe "[plugins-cli > $global:TEST_TAG] Use a custom jenkins.war" -Skip:(-not $global:TEST_TAG.StartsWith('jdk21-')) {
   It 'builds child image' {
     $exitCode, $stdout, $stderr = Build-DockerChild $global:SUT_IMAGE-plugins-cli-custom-war $PSScriptRoot/plugins-cli/custom-war --no-cache
     $exitCode | Should -Be 0
diff --git a/tests/runtime.Tests.ps1 b/tests/runtime.Tests.ps1
index 137d8e96f7..de7e7503ec 100644
--- a/tests/runtime.Tests.ps1
+++ b/tests/runtime.Tests.ps1
@@ -26,7 +26,8 @@ Describe "[runtime > $global:TEST_TAG] cleanup container" {
   }
 }
 
-Describe "[runtime > $global:TEST_TAG] test multiple JENKINS_OPTS" {
+# Only test on Java 21, one JDK is enough to test all versions
+Describe "[runtime > $global:TEST_TAG] test multiple JENKINS_OPTS" -Skip:(-not $global:TEST_TAG.StartsWith('jdk21-')) {
   It '"--help --version" should return the version, not the help' {
     # need the last line of output
     $exitCode, $stdout, $stderr = Run-Program 'docker.exe' "run --rm -e JENKINS_OPTS=`"--help --version`" --name $global:SUT_CONTAINER -P $global:SUT_IMAGE"
@@ -35,7 +36,8 @@ Describe "[runtime > $global:TEST_TAG] test multiple JENKINS_OPTS" {
   }
 }
 
-Describe "[runtime > $global:TEST_TAG] test jenkins arguments" {
+# Only test on Java 21, one JDK is enough to test all versions
+Describe "[runtime > $global:TEST_TAG] test jenkins arguments" -Skip:(-not $global:TEST_TAG.StartsWith('jdk21-')) {
   It 'running --help --version should return the version, not the help' {
     # need the last line of output
     $exitCode, $stdout, $stderr = Run-Program 'docker.exe' "run --rm --name $global:SUT_CONTAINER -P $global:SUT_IMAGE --help --version"
@@ -56,7 +58,8 @@ Describe "[runtime > $global:TEST_TAG] test jenkins arguments" {
   }
 }
 
-Describe "[runtime > $global:TEST_TAG] passing JVM parameters" {
+# Only test on Java 21, one JDK is enough to test all versions
+Describe "[runtime > $global:TEST_TAG] passing JVM parameters" -Skip:(-not $global:TEST_TAG.StartsWith('jdk21-')) {
   BeforeAll {
     $tzSetting = '-Duser.timezone=Europe/Madrid'
     $tzRegex = [regex]::Escape("Europe/Madrid")