diff --git a/.github/workflows/android.yaml b/.github/workflows/android.yaml
index 5b6eb2555dc0..b0139064dfa9 100644
--- a/.github/workflows/android.yaml
+++ b/.github/workflows/android.yaml
@@ -33,6 +33,10 @@ jobs:
       matrix:
         working_directory:
           ['tests', 'packages/cloud_firestore/cloud_firestore/example']
+    env:
+      AVD_ARCH: x86_64
+      AVD_API_LEVEL: 34
+      AVD_TARGET: google_apis
     steps:
       - uses: actions/checkout@d632683dd7b4114ad314bca15554477dd762a938
       - uses: actions/setup-node@1d0ff469b7ec7b3cb9d8673fde0c81c44821de2a
@@ -43,11 +47,20 @@ jobs:
         with:
           distribution: 'temurin'
           java-version: '17'
+      - name: 'Install Tools'
+        run: |
+          sudo npm i -g firebase-tools
+          echo "FIREBASE_TOOLS_VERSION=$(npm firebase --version)" >> $GITHUB_ENV
       - name: Firebase Emulator Cache
-        uses: actions/cache@1bd1e32a3bdc45362d1e726936510720a7c30a57
+        id: firebase-emulator-cache
+        uses: actions/cache/restore@1bd1e32a3bdc45362d1e726936510720a7c30a57
+        continue-on-error: true
         with:
+          # The firebase emulators are pure javascript and java, OS-independent
+          enableCrossOsArchive: true
+          # Must match the save path exactly
           path: ~/.cache/firebase/emulators
-          key: firebase-emulators-v3-${{ runner.os }}
+          key: firebase-emulators-v3-${{ env.FIREBASE_TOOLS_VERSION }}
           restore-keys: firebase-emulators-v3
       - uses: subosito/flutter-action@f2c4f6686ca8e8d6e6d0f28410eeef506ed66aff
         with:
@@ -61,9 +74,6 @@ jobs:
           melos-version: '5.3.0'
       - name: 'Bootstrap package'
         run: melos bootstrap --scope tests && melos bootstrap --scope "cloud_firestore*"
-      - name: 'Install Tools'
-        run: |
-          sudo npm i -g firebase-tools
       - name: Start Firebase Emulator
         run: cd ./.github/workflows/scripts && ./start-firebase-emulator.sh
       - name: Enable KVM
@@ -82,19 +92,21 @@ jobs:
           remove-docker-images: true
           remove-large-packages: true
       - name: AVD cache
-        uses: actions/cache@1bd1e32a3bdc45362d1e726936510720a7c30a57
+        uses: actions/cache/restore@1bd1e32a3bdc45362d1e726936510720a7c30a57
+        continue-on-error: true
         id: avd-cache
         with:
+          # Must match the save path exactly
           path: |
             ~/.android/avd/*
             ~/.android/adb*
-          key: avd-${{ runner.os }}
+          key: avd-${{ runner.os }}-${{ env.AVD_API_LEVEL }}-${{ env.AVD_TARGET }}-${{ env.AVD_ARCH }}
       - name: Start AVD then run E2E tests
-        uses: reactivecircus/android-emulator-runner@v2
+        uses: reactivecircus/android-emulator-runner@b530d96654c385303d652368551fb075bc2f0b6b
         with:
-          api-level: 34
-          target: google_apis
-          arch: x86_64
+          api-level: ${{ env.AVD_API_LEVEL }}
+          target: ${{ env.AVD_TARGET }}
+          arch: ${{ env.AVD_ARCH }}
           working-directory: ${{ matrix.working_directory }}
           script: |
             flutter test integration_test/e2e_test.dart --ignore-timeouts --dart-define=CI=true -d emulator-5554
@@ -103,3 +115,21 @@ jobs:
       # https://github.com/ReactiveCircus/android-emulator-runner/issues/385
         run: |
           pgrep -f appium && pkill -f appium || echo "No Appium process found"
+      - name: Save Firestore Emulator Cache
+        # Branches can read main cache but main cannot read branch cache. Avoid LRU eviction with main-only cache.
+        if: github.ref == 'refs/heads/main'
+        uses: actions/cache/save@1bd1e32a3bdc45362d1e726936510720a7c30a57
+        with:
+          key: ${{ steps.firebase-emulator-cache.outputs.cache-primary-key }}
+          # Must match the restore path exactly
+          path: ~/.cache/firebase/emulators
+      - name: Save Android Emulator Cache
+        # Branches can read main cache but main cannot read branch cache. Avoid LRU eviction with main-only cache.
+        if: github.ref == 'refs/heads/main'
+        uses: actions/cache/save@1bd1e32a3bdc45362d1e726936510720a7c30a57
+        with:
+          key: ${{ steps.avd-cache.outputs.cache-primary-key }}
+          # Must match the restore path exactly
+          path: |
+            ~/.android/avd/*
+            ~/.android/adb*
diff --git a/.github/workflows/e2e_tests_fdc.yaml b/.github/workflows/e2e_tests_fdc.yaml
index d252f8fed582..5b0305c4acb6 100644
--- a/.github/workflows/e2e_tests_fdc.yaml
+++ b/.github/workflows/e2e_tests_fdc.yaml
@@ -27,6 +27,10 @@ jobs:
     timeout-minutes: 45
     strategy:
       fail-fast: false
+    env:
+      AVD_ARCH: x86_64
+      AVD_API_LEVEL: 34
+      AVD_TARGET: google_apis
     steps:
       - uses: actions/checkout@d632683dd7b4114ad314bca15554477dd762a938
       - uses: actions/setup-node@1d0ff469b7ec7b3cb9d8673fde0c81c44821de2a
@@ -37,11 +41,20 @@ jobs:
         with:
           distribution: 'temurin'
           java-version: '17'
+      - name: 'Install Tools'
+        run: |
+          sudo npm i -g firebase-tools
+          echo "FIREBASE_TOOLS_VERSION=$(npm firebase --version)" >> $GITHUB_ENV
       - name: Firebase Emulator Cache
-        uses: actions/cache@1bd1e32a3bdc45362d1e726936510720a7c30a57
+        id: firebase-emulator-cache
+        uses: actions/cache/restore@1bd1e32a3bdc45362d1e726936510720a7c30a57
+        continue-on-error: true
         with:
+          # The firebase emulators are pure javascript and java, OS-independent
+          enableCrossOsArchive: true
+          # Must match the save path exactly
           path: ~/.cache/firebase/emulators
-          key: firebase-emulators-v3-fdc-${{ runner.os }}
+          key: firebase-emulators-v3-${{ env.FIREBASE_TOOLS_VERSION }}
           restore-keys: firebase-emulators-v3
       - uses: subosito/flutter-action@f2c4f6686ca8e8d6e6d0f28410eeef506ed66aff
         with:
@@ -55,9 +68,6 @@ jobs:
           melos-version: '5.3.0'
       - name: 'Bootstrap package'
         run: melos bootstrap --scope "firebase_data_connect*"
-      - name: 'Install Tools'
-        run: |
-          sudo npm i -g firebase-tools
       - name: Start Firebase Emulator
         run: |
           cd ./packages/firebase_data_connect/firebase_data_connect/example
@@ -80,22 +90,44 @@ jobs:
           remove-docker-images: true
           remove-large-packages: true
       - name: AVD cache
-        uses: actions/cache@1bd1e32a3bdc45362d1e726936510720a7c30a57
+        uses: actions/cache/restore@1bd1e32a3bdc45362d1e726936510720a7c30a57
         id: avd-cache
+        continue-on-error: true
         with:
+          # Must match the save path exactly
           path: |
             ~/.android/avd/*
             ~/.android/adb*
-          key: avd-${{ runner.os }}
+          key: avd-${{ runner.os }}-${{ env.AVD_API_LEVEL }}-${{ env.AVD_TARGET }}-${{ env.AVD_ARCH }}
       - name: Start AVD then run E2E tests
         uses: reactivecircus/android-emulator-runner@v2
         with:
-          api-level: 34
-          target: google_apis
-          arch: x86_64
+          api-level: ${{ env.AVD_API_LEVEL }}
+          target: ${{ env.AVD_TARGET }}
+          arch: ${{ env.AVD_ARCH }}
           working-directory: 'packages/firebase_data_connect/firebase_data_connect/example'
           script: |
             flutter test integration_test/e2e_test.dart --dart-define=CI=true -d emulator-5554
+      - name: Save Android Emulator Cache
+        # Branches can read main cache but main cannot read branch cache. Avoid LRU eviction with main-only cache.
+        if: github.ref == 'refs/heads/main'
+        uses: actions/cache/save@1bd1e32a3bdc45362d1e726936510720a7c30a57
+        continue-on-error: true
+        with:
+          key: ${{ steps.avd-cache.outputs.cache-primary-key }}
+          # Must match the restore path exactly
+          path: |
+            ~/.android/avd/*
+            ~/.android/adb*
+      - name: Save Firestore Emulator Cache
+        # Branches can read main cache but main cannot read branch cache. Avoid LRU eviction with main-only cache.
+        if: github.ref == 'refs/heads/main'
+        uses: actions/cache/save@1bd1e32a3bdc45362d1e726936510720a7c30a57
+        continue-on-error: true
+        with:
+          key: ${{ steps.firebase-emulator-cache.outputs.cache-primary-key }}
+          # Must match the restore path exactly
+          path: ~/.cache/firebase/emulators
 
   ios:
     runs-on: macos-15
@@ -121,18 +153,29 @@ jobs:
         with:
           key: xcode-cache-${{ runner.os }}
           max-size: 700M
-      - uses: actions/cache@1bd1e32a3bdc45362d1e726936510720a7c30a57
+      - uses: actions/cache/restore@1bd1e32a3bdc45362d1e726936510720a7c30a57
+        continue-on-error: true
         name: Pods Cache
         id: pods-cache
         with:
+          # Must match the save path exactly
           path: tests/ios/Pods
           key: ${{ runner.os }}-fdc-pods-v3-${{ hashFiles('tests/ios/Podfile.lock') }}
           restore-keys: ${{ runner.os }}-ios-pods-v2
+      - name: 'Install Tools'
+        run: |
+          sudo npm i -g firebase-tools
+          echo "FIREBASE_TOOLS_VERSION=$(npm firebase --version)" >> $GITHUB_ENV
       - name: Firebase Emulator Cache
-        uses: actions/cache@1bd1e32a3bdc45362d1e726936510720a7c30a57
+        id: firebase-emulator-cache
+        uses: actions/cache/restore@1bd1e32a3bdc45362d1e726936510720a7c30a57
+        continue-on-error: true
         with:
+          # The firebase emulators are pure javascript and java, OS-independent
+          enableCrossOsArchive: true
+          # Must match the save path exactly
           path: ~/.cache/firebase/emulators
-          key: firebase-emulators-v3-fdc-${{ runner.os }}
+          key: firebase-emulators-v3-${{ env.FIREBASE_TOOLS_VERSION }}
           restore-keys: firebase-emulators-v3
       - uses: subosito/flutter-action@f2c4f6686ca8e8d6e6d0f28410eeef506ed66aff
         with:
@@ -144,9 +187,6 @@ jobs:
           melos-version: '5.3.0'
       - name: 'Bootstrap package'
         run: melos bootstrap --scope "firebase_data_connect*"
-      - name: 'Install Tools'
-        run: |
-          sudo npm i -g firebase-tools
       - name: 'Build Application'
         working-directory: 'packages/firebase_data_connect/firebase_data_connect/example'
         run: |
@@ -178,6 +218,24 @@ jobs:
           # Uncomment following line to have simulator logs printed out for debugging purposes.
           # xcrun simctl spawn booted log stream --predicate 'eventMessage contains "flutter"' &
           flutter test integration_test/e2e_test.dart -d "$SIMULATOR" --dart-define=CI=true
+      - name: Save Firestore Emulator Cache
+        # Branches can read main cache but main cannot read branch cache. Avoid LRU eviction with main-only cache.
+        if: github.ref == 'refs/heads/main'
+        uses: actions/cache/save@1bd1e32a3bdc45362d1e726936510720a7c30a57
+        continue-on-error: true
+        with:
+          key: ${{ steps.firebase-emulator-cache.outputs.cache-primary-key }}
+          # Must match the restore path exactly
+          path: ~/.cache/firebase/emulators
+      - name: Save Pods Cache
+        # Branches can read main cache but main cannot read branch cache. Avoid LRU eviction with main-only cache.
+        if: github.ref == 'refs/heads/main'
+        uses: actions/cache/save@1bd1e32a3bdc45362d1e726936510720a7c30a57
+        continue-on-error: true
+        with:
+          key: ${{ steps.pods-cache.outputs.cache-primary-key }}
+          # Must match the restore paths exactly
+          path: tests/ios/Pods
 
   web:
     runs-on: macos-latest
@@ -207,12 +265,19 @@ jobs:
       - name: 'Bootstrap package'
         run: melos bootstrap --scope "firebase_data_connect*"
       - name: 'Install Tools'
-        run: sudo npm i -g firebase-tools
-      - name: Cache Firebase Emulator
-        uses: actions/cache@1bd1e32a3bdc45362d1e726936510720a7c30a57
+        run: |
+          sudo npm i -g firebase-tools
+          echo "FIREBASE_TOOLS_VERSION=$(npm firebase --version)" >> $GITHUB_ENV
+     - name: Firebase Emulator Cache
+        id: firebase-emulator-cache
+        uses: actions/cache/restore@1bd1e32a3bdc45362d1e726936510720a7c30a57
+        continue-on-error: true
         with:
+          # The firebase emulators are pure javascript and java, OS-independent
+          enableCrossOsArchive: true
+          # Must match the save path exactly
           path: ~/.cache/firebase/emulators
-          key: firebase-emulators-v3-fdc-${{ runner.os }}
+          key: firebase-emulators-v3-${{ env.FIREBASE_TOOLS_VERSION }}
           restore-keys: firebase-emulators-v3
       - name: Start Firebase Emulator
         run: |
@@ -237,3 +302,21 @@ jobs:
           exit 1
           fi
         shell: bash
+      - name: Save Firestore Emulator Cache
+        # Branches can read main cache but main cannot read branch cache. Avoid LRU eviction with main-only cache.
+        if: github.ref == 'refs/heads/main'
+        uses: actions/cache/save@1bd1e32a3bdc45362d1e726936510720a7c30a57
+        continue-on-error: true
+        with:
+          key: ${{ steps.firebase-emulator-cache.outputs.cache-primary-key }}
+          # Must match the restore path exactly
+          path: ~/.cache/firebase/emulators
+      - name: Save Pods Cache
+        # Branches can read main cache but main cannot read branch cache. Avoid LRU eviction with main-only cache.
+        if: github.ref == 'refs/heads/main'
+        uses: actions/cache/save@1bd1e32a3bdc45362d1e726936510720a7c30a57
+        continue-on-error: true
+        with:
+          key: ${{ steps.pods-cache.outputs.cache-primary-key }}
+          # Must match the restore paths exactly
+          path: tests/ios/Pods
diff --git a/.github/workflows/ios.yaml b/.github/workflows/ios.yaml
index 28865c50d745..02ccb0fafbdb 100644
--- a/.github/workflows/ios.yaml
+++ b/.github/workflows/ios.yaml
@@ -50,18 +50,29 @@ jobs:
         with:
           key: xcode-cache-${{ runner.os }}
           max-size: 700M
-      - uses: actions/cache@1bd1e32a3bdc45362d1e726936510720a7c30a57
+      - uses: actions/cache/restore@1bd1e32a3bdc45362d1e726936510720a7c30a57
+        continue-on-error: true
         name: Pods Cache
         id: pods-cache
         with:
+          # Must match the save path exactly
           path: tests/ios/Pods
           key: pods-v3-${{ runner.os }}-${{ hashFiles('tests/ios/Podfile.lock') }}
           restore-keys: pods-v3-${{ runner.os }}
+      - name: 'Install Tools'
+        run: |
+          sudo npm i -g firebase-tools
+          echo "FIREBASE_TOOLS_VERSION=$(npm firebase --version)" >> $GITHUB_ENV
       - name: Firebase Emulator Cache
-        uses: actions/cache@1bd1e32a3bdc45362d1e726936510720a7c30a57
+        id: firebase-emulator-cache
+        uses: actions/cache/restore@1bd1e32a3bdc45362d1e726936510720a7c30a57
+        continue-on-error: true
         with:
+          # The firebase emulators are pure javascript and java, OS-independent
+          enableCrossOsArchive: true
+          # Must match the save path exactly
           path: ~/.cache/firebase/emulators
-          key: firebase-emulators-v3-${{ runner.os }}
+          key: firebase-emulators-v3-${{ env.FIREBASE_TOOLS_VERSION }}
           restore-keys: firebase-emulators-v3
       - uses: subosito/flutter-action@f2c4f6686ca8e8d6e6d0f28410eeef506ed66aff
         with:
@@ -75,9 +86,6 @@ jobs:
           melos-version: '5.3.0'
       - name: 'Bootstrap package'
         run: melos bootstrap --scope tests && melos bootstrap --scope "cloud_firestore*"
-      - name: 'Install Tools'
-        run: |
-          sudo npm i -g firebase-tools
       - name: 'Free up space'
         run: |
           sudo rm -rf \
@@ -118,3 +126,21 @@ jobs:
           # Uncomment following line to have simulator logs printed out for debugging purposes.
           # xcrun simctl spawn booted log stream --predicate 'eventMessage contains "flutter"' &
           flutter test integration_test/e2e_test.dart -d "$SIMULATOR" --ignore-timeouts --dart-define=CI=true
+      - name: Save Firestore Emulator Cache
+        # Branches can read main cache but main cannot read branch cache. Avoid LRU eviction with main-only cache.
+        if: github.ref == 'refs/heads/main'
+        uses: actions/cache/save@1bd1e32a3bdc45362d1e726936510720a7c30a57
+        continue-on-error: true
+        with:
+          key: ${{ steps.firebase-emulator-cache.outputs.cache-primary-key }}
+          # Must match the restore paths exactly
+          path: ~/.cache/firebase/emulators
+      - name: Save Pods Cache
+        # Branches can read main cache but main cannot read branch cache. Avoid LRU eviction with main-only cache.
+        if: github.ref == 'refs/heads/main'
+        uses: actions/cache/save@1bd1e32a3bdc45362d1e726936510720a7c30a57
+        continue-on-error: true
+        with:
+          key: ${{ steps.pods-cache.outputs.cache-primary-key }}
+          # Must match the restore paths exactly
+          path: tests/ios/Pods
diff --git a/.github/workflows/macos.yaml b/.github/workflows/macos.yaml
index 4c4e8a6ba03f..fd0b77bebc75 100644
--- a/.github/workflows/macos.yaml
+++ b/.github/workflows/macos.yaml
@@ -48,18 +48,29 @@ jobs:
         with:
           key: xcode-cache-${{ runner.os }}
           max-size: 700M
-      - uses: actions/cache@1bd1e32a3bdc45362d1e726936510720a7c30a57
         name: Pods Cache
+        continue-on-error: true
+        uses: actions/cache/restore@1bd1e32a3bdc45362d1e726936510720a7c30a57
         id: pods-cache
         with:
+          # Must match the save path exactly
           path: tests/macos/Pods
           key: pods-v3-${{ runner.os }}-${{ hashFiles('tests/macos/Podfile.lock') }}
           restore-keys: pods-v3-${{ runner.os }}
-      - name: Cache Firebase Emulator
-        uses: actions/cache@1bd1e32a3bdc45362d1e726936510720a7c30a57
+      - name: 'Install Tools'
+        run: |
+          sudo npm i -g firebase-tools
+          echo "FIREBASE_TOOLS_VERSION=$(npm firebase --version)" >> $GITHUB_ENV
+      - name: Firebase Emulator Cache
+        id: firebase-emulator-cache
+        uses: actions/cache/restore@1bd1e32a3bdc45362d1e726936510720a7c30a57
+        continue-on-error: true
         with:
+          # The firebase emulators are pure javascript and java, OS-independent
+          enableCrossOsArchive: true
+          # Must match the save path exactly
           path: ~/.cache/firebase/emulators
-          key: firebase-emulators-v3-${{ runner.os }}
+          key: firebase-emulators-v3-${{ env.FIREBASE_TOOLS_VERSION }}
           restore-keys: firebase-emulators-v3
       - uses: subosito/flutter-action@f2c4f6686ca8e8d6e6d0f28410eeef506ed66aff
         with:
@@ -73,9 +84,6 @@ jobs:
           melos-version: '5.3.0'
       - name: 'Bootstrap package'
         run: melos bootstrap --scope tests && melos bootstrap --scope "cloud_firestore*"
-      - name: 'Install Tools'
-        run: |
-          sudo npm i -g firebase-tools
       - name: 'Build Application'
         working-directory: ${{ matrix.working_directory }}
         run: |
@@ -98,3 +106,21 @@ jobs:
             -d macos \
             --dart-define=CI=true \
             --ignore-timeouts
+      - name: Save Firestore Emulator Cache
+        continue-on-error: true
+        # Branches can read main cache but main cannot read branch cache. Avoid LRU eviction with main-only cache.
+        if: github.ref == 'refs/heads/main'
+        uses: actions/cache/save@1bd1e32a3bdc45362d1e726936510720a7c30a57
+        with:
+          key: ${{ steps.firebase-emulator-cache.outputs.cache-primary-key }}
+          # Must match the restore path exactly
+          path: ~/.cache/firebase/emulators
+      - name: Save Pods Cache
+        continue-on-error: true
+        # Branches can read main cache but main cannot read branch cache. Avoid LRU eviction with main-only cache.
+        if: github.ref == 'refs/heads/main'
+        uses: actions/cache/save@1bd1e32a3bdc45362d1e726936510720a7c30a57
+        with:
+          key: ${{ steps.pods-cache.outputs.cache-primary-key }}
+          # Must match the restore paths exactly
+          path: tests/ios/Pods
diff --git a/.github/workflows/web.yaml b/.github/workflows/web.yaml
index 3866161422f6..c69b3118b45c 100644
--- a/.github/workflows/web.yaml
+++ b/.github/workflows/web.yaml
@@ -56,12 +56,19 @@ jobs:
       - name: 'Bootstrap package'
         run: melos bootstrap --scope tests && melos bootstrap --scope "cloud_firestore*"
       - name: 'Install Tools'
-        run: sudo npm i -g firebase-tools
-      - name: Cache Firebase Emulator
-        uses: actions/cache@1bd1e32a3bdc45362d1e726936510720a7c30a57
+        run: |
+          sudo npm i -g firebase-tools
+          echo "FIREBASE_TOOLS_VERSION=$(npm firebase --version)" >> $GITHUB_ENV
+      - name: Firebase Emulator Cache
+        id: firebase-emulator-cache
+        uses: actions/cache/restore@1bd1e32a3bdc45362d1e726936510720a7c30a57
+        continue-on-error: true
         with:
+          # The firebase emulators are pure javascript and java, OS-independent
+          enableCrossOsArchive: true
+          # Must match the save path exactly
           path: ~/.cache/firebase/emulators
-          key: firebase-emulators-v3-${{ runner.os }}
+          key: firebase-emulators-v3-${{ env.FIREBASE_TOOLS_VERSION }}
           restore-keys: firebase-emulators-v3
       - name: Start Firebase Emulator
         run: sudo chown -R 501:20 "/Users/runner/.npm" && cd ./.github/workflows/scripts && ./start-firebase-emulator.sh
@@ -81,6 +88,15 @@ jobs:
           exit 1
           fi
         shell: bash
+      - name: Save Firestore Emulator Cache
+        # Branches can read main cache but main cannot read branch cache. Avoid LRU eviction with main-only cache.
+        if: github.ref == 'refs/heads/main'
+        continue-on-error: true
+        uses: actions/cache/save@1bd1e32a3bdc45362d1e726936510720a7c30a57
+        with:
+          key: ${{ steps.firebase-emulator-cache.outputs.cache-primary-key }}
+          # Must match the restore path exactly
+          path: ~/.cache/firebase/emulators
 
   web-app-check:
     runs-on: macos-latest
@@ -108,12 +124,19 @@ jobs:
       - name: 'Bootstrap package'
         run: melos bootstrap --scope tests
       - name: 'Install Tools'
-        run: sudo npm i -g firebase-tools
-      - name: Cache Firebase Emulator
-        uses: actions/cache@1bd1e32a3bdc45362d1e726936510720a7c30a57
+        run: |
+          sudo npm i -g firebase-tools
+          echo "FIREBASE_TOOLS_VERSION=$(npm firebase --version)" >> $GITHUB_ENV
+      - name: Firebase Emulator Cache
+        id: firebase-emulator-cache
+        uses: actions/cache/restore@1bd1e32a3bdc45362d1e726936510720a7c30a57
+        continue-on-error: true
         with:
+          # The firebase emulators are pure javascript and java, OS-independent
+          enableCrossOsArchive: true
+          # Must match the save path exactly
           path: ~/.cache/firebase/emulators
-          key: firebase-emulators-v3-${{ runner.os }}
+          key: firebase-emulators-v3-${{ env.FIREBASE_TOOLS_VERSION }}
           restore-keys: firebase-emulators-v3
       - name: Start Firebase Emulator
         run: sudo chown -R 501:20 "/Users/runner/.npm" && cd ./.github/workflows/scripts && ./start-firebase-emulator.sh
@@ -133,6 +156,15 @@ jobs:
           exit 1
           fi
         shell: bash
+      - name: Save Firestore Emulator Cache
+        # Branches can read main cache but main cannot read branch cache. Avoid LRU eviction with main-only cache.
+        if: github.ref == 'refs/heads/main'
+        uses: actions/cache/save@1bd1e32a3bdc45362d1e726936510720a7c30a57
+        continue-on-error: true
+        with:
+          key: ${{ steps.firebase-emulator-cache.outputs.cache-primary-key }}
+          # Must match the restore path exactly
+          path: ~/.cache/firebase/emulators
 
   web-wasm:
     runs-on: macos-latest
@@ -165,12 +197,19 @@ jobs:
       - name: 'Bootstrap package'
         run: melos bootstrap --scope tests && melos bootstrap --scope "cloud_firestore*"
       - name: 'Install Tools'
-        run: sudo npm i -g firebase-tools
-      - name: Cache Firebase Emulator
-        uses: actions/cache@1bd1e32a3bdc45362d1e726936510720a7c30a57
+        run: |
+          sudo npm i -g firebase-tools
+          echo "FIREBASE_TOOLS_VERSION=$(npm firebase --version)" >> $GITHUB_ENV
+      - name: Firebase Emulator Cache
+        id: firebase-emulator-cache
+        uses: actions/cache/restore@1bd1e32a3bdc45362d1e726936510720a7c30a57
+        continue-on-error: true
         with:
+          # The firebase emulators are pure javascript and java, OS-independent
+          enableCrossOsArchive: true
+          # Must match the save path exactly
           path: ~/.cache/firebase/emulators
-          key: firebase-emulators-v3-${{ runner.os }}
+          key: firebase-emulators-v3-${{ env.FIREBASE_TOOLS_VERSION }}
           restore-keys: firebase-emulators-v3
       - name: Start Firebase Emulator
         run: sudo chown -R 501:20 "/Users/runner/.npm" && cd ./.github/workflows/scripts && ./start-firebase-emulator.sh
@@ -191,3 +230,12 @@ jobs:
           exit 1
           fi
         shell: bash
+      - name: Save Firestore Emulator Cache
+        # Branches can read main cache but main cannot read branch cache. Avoid LRU eviction with main-only cache.
+        if: github.ref == 'refs/heads/main'
+        uses: actions/cache/save@1bd1e32a3bdc45362d1e726936510720a7c30a57
+        continue-on-error: true
+        with:
+          key: ${{ steps.firebase-emulator-cache.outputs.cache-primary-key }}
+          # Must match the restore path exactly
+          path: ~/.cache/firebase/emulators