diff --git a/.github/workflows/doxygen.yml b/.github/workflows/doxygen.yml
new file mode 100644
index 0000000000..40fabd42e0
--- /dev/null
+++ b/.github/workflows/doxygen.yml
@@ -0,0 +1,64 @@
+name: Doxygen
+
+on:
+  push:
+    branches: [ master, v5.14, v5.16, v5.18, v6.1 ]
+
+  workflow_dispatch:
+
+jobs:
+  build:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v2
+        with:
+          path: ./paparazzi
+          submodules: recursive
+
+      - uses: actions/checkout@v2
+        with:
+          repository: 'paparazzi/paparazzi.github.com'
+          path: ./site
+          token: ${{ secrets.PUSH_TOKEN }}
+          
+      - name: Set env
+        run: |
+          BRANCH_NAME=${GITHUB_REF_NAME/master/latest}
+          echo "build doc for $BRANCH_NAME..."
+          echo "BRANCH_NAME=$BRANCH_NAME" >> $GITHUB_ENV
+      
+      - name: Install dependencies
+        run: sudo apt-get update && sudo apt-get install -y doxygen graphviz doxygen-latex
+      
+      - name: Generate doc for modules and messages from XML files
+        run: |
+          export PAPARAZZI_HOME=$(realpath -e paparazzi)
+          export PAPARAZZI_SRC=$(realpath -e paparazzi)
+          ./paparazzi/sw/tools/doxygen_gen/gen_modules_doc.py -pv
+          ./paparazzi/sw/tools/doxygen_gen/gen_messages_doc.py -pv
+
+      - name: prepare doxygen conf
+        run: |
+          echo "OUTPUT_DIRECTORY=$(realpath output)" >> paparazzi/Doxyfile
+          echo "HTML_OUTPUT=./" >> paparazzi/Doxyfile
+          echo "PROJECT_NUMBER=$(./paparazzi/paparazzi_version)" >> paparazzi/Doxyfile
+          echo "QUIET=YES" >> paparazzi/Doxyfile
+       
+      - name: build doxygen
+        run: cd paparazzi && doxygen
+      
+      - name: copy and commit changes
+        run: |
+          rm -rf site/$BRANCH_NAME
+          cp -r output site/$BRANCH_NAME
+          cd site
+          git config --local user.email "github-actions[bot]@users.noreply.github.com"
+          git config --local user.name "github-actions[bot]"
+          git add -A
+          git commit -m "Generated doxygen docs for $BRANCH_NAME."
+          git push https://$USERNAME:$REPO_KEY@github.com/paparazzi/paparazzi.github.com.git
+        env:
+          REPO_KEY: ${{secrets.PUSH_TOKEN}}
+          USERNAME: github-actions[bot]
+
+
diff --git a/sw/tools/doxygen_gen/gen_messages_doc.py b/sw/tools/doxygen_gen/gen_messages_doc.py
index 3c091a3fb2..3c403651e3 100755
--- a/sw/tools/doxygen_gen/gen_messages_doc.py
+++ b/sw/tools/doxygen_gen/gen_messages_doc.py
@@ -20,7 +20,7 @@ def print_field(field):
     # if values are given, put those in the unit column
     if not unit:
         values = field.get('values', '')
-        unit = string.replace(values, '|', ', ')
+        unit = values.replace('|', ', ')
     return u"{name} | {type} | {unit} | {desc} |\n".format(name=name, type=type, desc=desc, unit=unit)
 
 
@@ -136,7 +136,7 @@ if __name__ == '__main__':
     messages = read_messages_file(messages_file)
 
     # generate string containing markdown page
-    outstring = messages_page(messages).encode('utf-8')
+    outstring = messages_page(messages)
 
     #print(outstring)
 
diff --git a/sw/tools/doxygen_gen/gen_modules_doc.py b/sw/tools/doxygen_gen/gen_modules_doc.py
index 27ff80abd7..5e7d11d589 100755
--- a/sw/tools/doxygen_gen/gen_modules_doc.py
+++ b/sw/tools/doxygen_gen/gen_modules_doc.py
@@ -118,7 +118,7 @@ def get_xml_example(filename, module):
             e = copy.deepcopy(o)
             if 'description' in e.attrib:
                 del e.attrib['description']
-            s += "  " + string.strip(ET.tostring(e)) + "\n"
+            s += "  " + str(ET.tostring(e)).strip() + "\n"
         s += "</module>\n"
     else:
         s += '<module name="{0}"/>\n'.format(module_name)