diff --git a/.github/workflows/generate-ebooks.yml b/.github/workflows/generate-ebooks.yml
new file mode 100644
index 00000000000..38053001241
--- /dev/null
+++ b/.github/workflows/generate-ebooks.yml
@@ -0,0 +1,63 @@
+######################################
+## Custom Web Almanac GitHub action ##
+######################################
+#
+# A script that must be run in GitHub Actions to generate the ebooks.
+# Useful for those that don't have prince installed locally.
+#
+name: Generate ebooks
+
+env:
+  # Update periodically from https://www.princexml.com/latest/
+  PRINCE_PACKAGE: 'prince_16.1-1_ubuntu24.04_amd64.deb'
+
+on:
+  workflow_dispatch:
+
+jobs:
+  build:
+    name: Generate Ebooks
+    runs-on: ubuntu-latest
+    steps:
+    - name: Checkout branch
+      uses: actions/checkout@v7
+    - name: Setup Node.js for use with actions
+      uses: actions/setup-node@v7
+      with:
+        node-version: '24'
+    - name: Set up Python 3.12
+      uses: actions/setup-python@v7
+      with:
+        python-version: '3.12'
+    - name: Install Asian Fonts
+      if: ${{ github.event.inputs.ebooks == 'true' }}
+      run: |
+        # Install Japanese san-serif font
+        sudo apt-get install -y fonts-ipafont-gothic
+        # Install Chinese san-serif font
+        sudo apt-get install -y fonts-arphic-uming
+        # Install Korean san-serif font
+        sudo apt-get install -y fonts-unfonts-core
+    - name: Install PrinceXML
+      if: ${{ github.event.inputs.ebooks == 'true' }}
+      run: |
+        wget https://www.princexml.com/download/${{ env.PRINCE_PACKAGE }} --directory-prefix=/tmp
+        DEBIAN_FRONTEND=noninteractive sudo apt install -y /tmp/${{ env.PRINCE_PACKAGE }}
+    - name: Install pdftk
+      if: ${{ github.event.inputs.ebooks == 'true' }}
+      run: sudo apt install pdftk
+    - name: Run the website
+      run: ./src/tools/scripts/run_and_test_website.sh
+    - name: Generating Ebooks
+      run: |
+        cd src
+        mkdir static/pdfs/
+        npm run ebooks
+    - name: Upload PDF artifact
+      if: ${{ github.event.inputs.ebooks == 'true' }}
+      uses: actions/upload-artifact@v7
+      with:
+        name: pdfs
+        path: ./src/static/pdfs/*.pdf
+        if-no-files-found: warn # 'warn' or 'ignore' are also available, defaults to `warn`
+        retention-days: 5 # defaults to 90
diff --git a/src/config/2025.json b/src/config/2025.json
index fa147a2a2c7..241112a95fc 100644
--- a/src/config/2025.json
+++ b/src/config/2025.json
@@ -3,7 +3,7 @@
     {
       "is_live": true,
       "supported_languages": ["de","en","es","fr","hi","it","ja","nl","pt","ru","tr","uk","zh-CN","zh-TW"],
-      "ebook_languages": ["en"]
+      "ebook_languages": ["en","ja"]
     }
   ],
   "outline": [
diff --git a/src/config/last_updated.json b/src/config/last_updated.json
index d1fd0dcac49..0d5a88b9219 100644
--- a/src/config/last_updated.json
+++ b/src/config/last_updated.json
@@ -235,6 +235,23 @@
     "date_modified": "2026-06-09T00:00:00.000Z",
     "hash": "1b4f831fe700d22363fcf6a84fffd009",
     "size": 12
+  },
+    "/static/pdfs/web_almanac_2025_ja.pdf": {
+    "date_published": "2026-08-10T00:00:00.000Z",
+    "date_modified": "2026-08-10T00:00:00.000Z",
+    "hash": "84fd8a59f723beed0e3f93dba2135542",
+    "size": 12
+  },
+  "/static/pdfs/web_almanac_2025_ja_cover_A5.pdf": {
+    "date_published": "2026-08-10T00:00:00.000Z",
+    "date_modified": "2026-08-10T00:00:00.000Z",
+    "hash": "b73962b439e73aadf6f22554e597adfc"
+  },
+  "/static/pdfs/web_almanac_2025_ja_print_A5.pdf": {
+    "date_published": "2026-08-10T00:00:00.000Z",
+    "date_modified": "2026-08-10T00:00:00.000Z",
+    "hash": "05c36794e850f494d862825794301586",
+    "size": 12
   },
   "en/2019/chapters/accessibility.html": {
     "date_published": "2019-11-11T00:00:00.000Z",
diff --git a/src/templates/base/base_ebook.html b/src/templates/base/base_ebook.html
index 3e65f05f45a..1bd451dfe0c 100644
--- a/src/templates/base/base_ebook.html
+++ b/src/templates/base/base_ebook.html
@@ -119,11 +119,15 @@
 
 {% set unit = 'mm' %}
 {% set spine = 25 %}
+{% if year == '2019' and lang == 'ja' %}{% set spine = 26.0 %}{% endif %}
 {% if year == '2020' and lang == 'en' %}{% set spine = 36.0 %}{% endif %}
 {% if year == '2020' and lang == 'ja' %}{% set spine = 37.0 %}{% endif %}
-{% if year == '2021' %}{% set spine = 46.5 %}{% endif %}
-{% if year == '2022' %}{% set spine = 42.5 %}{% endif %}
-{% if year == '2024' %}{% set spine = 42.5 %}{% endif %}
+{% if year == '2021' and lang == 'en' %}{% set spine = 46.5 %}{% endif %}
+{% if year == '2022' and lang == 'ja' %}{% set spine = 43.5 %}{% endif %}
+{% if year == '2024' and lang == 'en' %}{% set spine = 44.5 %}{% endif %}
+{% if year == '2024' and lang == 'ha' %}{% set spine = 46.0 %}{% endif %}
+{% if year == '2025' and lang == 'en' %}{% set spine = 33.5 %}{% endif %}
+{% if year == '2025' and lang == 'ja' %}{% set spine = 34.5 %}{% endif %}
 {% set pageWidth = 148 %}
 {% set pageHeight = 210 %}
 {% if request.args.get('unit') != None %}{% set unit = request.args.get('unit') %}{% endif %}