diff --git a/experimental/skottiekit/Makefile b/experimental/skottiekit/Makefile
index cf98418c7af8..5eb22a5343bd 100644
--- a/experimental/skottiekit/Makefile
+++ b/experimental/skottiekit/Makefile
@@ -45,4 +45,4 @@ clean_npm:
 
 serve:
 	echo "Go check out http://localhost:8001/"
-	cd examples && python ../serve.py
+	cd examples && python3 ../serve.py
diff --git a/experimental/skottiekit/serve.py b/experimental/skottiekit/serve.py
index 878d48dce408..a3e1f2687771 100644
--- a/experimental/skottiekit/serve.py
+++ b/experimental/skottiekit/serve.py
@@ -1,20 +1,21 @@
-# Copyright 2020 Google LLC
-
+#!/usr/bin/env python3
+# Copyright 2018 Google LLC
+#
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 
-import SimpleHTTPServer
-import SocketServer
+import http.server
+import socketserver
 
-PORT = 8001
+PORT = 8000
 
-class Handler(SimpleHTTPServer.SimpleHTTPRequestHandler):
+class Handler(http.server.SimpleHTTPRequestHandler):
     pass
 
 Handler.extensions_map['.js'] = 'application/javascript'
 # Without the correct MIME type, async compilation doesn't work
 Handler.extensions_map['.wasm'] = 'application/wasm'
 
-httpd = SocketServer.TCPServer(("", PORT), Handler)
+httpd = socketserver.TCPServer(("", PORT), Handler)
 
 httpd.serve_forever()
diff --git a/experimental/tskit/Makefile b/experimental/tskit/Makefile
index d5641c8baaf8..6eec614a1535 100644
--- a/experimental/tskit/Makefile
+++ b/experimental/tskit/Makefile
@@ -16,7 +16,7 @@ release:
 
 serve:
 	echo "Go check out http://localhost:8000/npm_build/example.html"
-	python2 serve.py
+	python3 serve.py
 
 lint:
 	npx eslint . --ext .ts
diff --git a/experimental/tskit/serve.py b/experimental/tskit/serve.py
index 8c6541f1fb1f..a3e1f2687771 100644
--- a/experimental/tskit/serve.py
+++ b/experimental/tskit/serve.py
@@ -1,20 +1,21 @@
+#!/usr/bin/env python3
 # Copyright 2018 Google LLC
-
+#
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 
-import SimpleHTTPServer
-import SocketServer
+import http.server
+import socketserver
 
 PORT = 8000
 
-class Handler(SimpleHTTPServer.SimpleHTTPRequestHandler):
+class Handler(http.server.SimpleHTTPRequestHandler):
     pass
 
 Handler.extensions_map['.js'] = 'application/javascript'
 # Without the correct MIME type, async compilation doesn't work
 Handler.extensions_map['.wasm'] = 'application/wasm'
 
-httpd = SocketServer.TCPServer(("", PORT), Handler)
+httpd = socketserver.TCPServer(("", PORT), Handler)
 
 httpd.serve_forever()
diff --git a/experimental/wasm-skp-debugger/serve.py b/experimental/wasm-skp-debugger/serve.py
index 8c6541f1fb1f..a3e1f2687771 100644
--- a/experimental/wasm-skp-debugger/serve.py
+++ b/experimental/wasm-skp-debugger/serve.py
@@ -1,20 +1,21 @@
+#!/usr/bin/env python3
 # Copyright 2018 Google LLC
-
+#
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 
-import SimpleHTTPServer
-import SocketServer
+import http.server
+import socketserver
 
 PORT = 8000
 
-class Handler(SimpleHTTPServer.SimpleHTTPRequestHandler):
+class Handler(http.server.SimpleHTTPRequestHandler):
     pass
 
 Handler.extensions_map['.js'] = 'application/javascript'
 # Without the correct MIME type, async compilation doesn't work
 Handler.extensions_map['.wasm'] = 'application/wasm'
 
-httpd = SocketServer.TCPServer(("", PORT), Handler)
+httpd = socketserver.TCPServer(("", PORT), Handler)
 
 httpd.serve_forever()
diff --git a/modules/canvaskit/Makefile b/modules/canvaskit/Makefile
index bdb150683427..1019f967ea37 100644
--- a/modules/canvaskit/Makefile
+++ b/modules/canvaskit/Makefile
@@ -98,7 +98,7 @@ local-example:
 	mkdir -p node_modules
 	ln -s ../npm_build node_modules/canvaskit
 	echo "Go check out http://localhost:8000/npm_build/example.html"
-	python2 serve.py
+	python3 serve.py
 
 test-continuous:
 	echo "Assuming npm ci has been run by user"
diff --git a/modules/canvaskit/serve.py b/modules/canvaskit/serve.py
index 8c6541f1fb1f..a3e1f2687771 100644
--- a/modules/canvaskit/serve.py
+++ b/modules/canvaskit/serve.py
@@ -1,20 +1,21 @@
+#!/usr/bin/env python3
 # Copyright 2018 Google LLC
-
+#
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 
-import SimpleHTTPServer
-import SocketServer
+import http.server
+import socketserver
 
 PORT = 8000
 
-class Handler(SimpleHTTPServer.SimpleHTTPRequestHandler):
+class Handler(http.server.SimpleHTTPRequestHandler):
     pass
 
 Handler.extensions_map['.js'] = 'application/javascript'
 # Without the correct MIME type, async compilation doesn't work
 Handler.extensions_map['.wasm'] = 'application/wasm'
 
-httpd = SocketServer.TCPServer(("", PORT), Handler)
+httpd = socketserver.TCPServer(("", PORT), Handler)
 
 httpd.serve_forever()
diff --git a/modules/canvaskit/wasm_tools/SIMD/build_simd_test.sh b/modules/canvaskit/wasm_tools/SIMD/build_simd_test.sh
index 00db15afba7f..69f8cb615d6d 100755
--- a/modules/canvaskit/wasm_tools/SIMD/build_simd_test.sh
+++ b/modules/canvaskit/wasm_tools/SIMD/build_simd_test.sh
@@ -33,4 +33,4 @@ grep -f wasm_simd_types.txt output/simd_test.wat
 # Serve the compiled WASM so output can be manually inspected for correctness.
 echo "Go check out http://localhost:8000/output/simd_test.html in Chrome Canary 86.0.4186.0 \
 or later and enable the chrome://flags#enable-webassembly-simd flag!"
-python ../../serve.py
+python3 ../../serve.py
diff --git a/modules/pathkit/Makefile b/modules/pathkit/Makefile
index b257e4425afd..10495ecec7cd 100644
--- a/modules/pathkit/Makefile
+++ b/modules/pathkit/Makefile
@@ -109,7 +109,7 @@ npm-debug:
 example:
 	npm install pathkit-asmjs pathkit-wasm
 	echo "Go check out localhost:8000/npm-wasm/example.html"
-	python serve.py
+	python3 serve.py
 
 local-example:
 	rm -rf node_modules/pathkit-wasm
@@ -119,7 +119,7 @@ local-example:
 	ln -s -T ../npm-asmjs node_modules/pathkit-asmjs
 	echo "Go check out http://localhost:8000/npm-wasm/example.html"
 	echo "or http://localhost:8000/npm-asmjs/example.html"
-	python serve.py
+	python3 serve.py
 
 local-example-test:
 	rm -rf node_modules/pathkit-wasm
@@ -130,7 +130,7 @@ local-example-test:
 	ln -s -T ../../npm-asmjs/bin/test node_modules/pathkit-asmjs/bin
 	echo "Go check out localhost:8000/npm-wasm/example.html"
 	echo "or http://localhost:8000/npm-asmjs/example.html"
-	python serve.py
+	python3 serve.py
 
 local-example-debug:
 	rm -rf node_modules/pathkit-wasm
@@ -141,5 +141,5 @@ local-example-debug:
 	ln -s -T ../../npm-asmjs/bin/debug node_modules/pathkit-asmjs/bin
 	echo "Go check out localhost:8000/npm-wasm/example.html"
 	echo "or http://localhost:8000/npm-asmjs/example.html"
-	python serve.py
+	python3 serve.py
 
diff --git a/modules/pathkit/compile.sh b/modules/pathkit/compile.sh
index 729d5c7d186b..01c1f42db314 100755
--- a/modules/pathkit/compile.sh
+++ b/modules/pathkit/compile.sh
@@ -127,6 +127,6 @@ ${BUILD_DIR}/libpathkit.a
 
 if [[ $@ == *serve* ]]; then
   pushd $BUILD_DIR
-  python serve.py
+  python3 serve.py
 fi
 
diff --git a/modules/pathkit/serve.py b/modules/pathkit/serve.py
index 8c6541f1fb1f..a3e1f2687771 100644
--- a/modules/pathkit/serve.py
+++ b/modules/pathkit/serve.py
@@ -1,20 +1,21 @@
+#!/usr/bin/env python3
 # Copyright 2018 Google LLC
-
+#
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 
-import SimpleHTTPServer
-import SocketServer
+import http.server
+import socketserver
 
 PORT = 8000
 
-class Handler(SimpleHTTPServer.SimpleHTTPRequestHandler):
+class Handler(http.server.SimpleHTTPRequestHandler):
     pass
 
 Handler.extensions_map['.js'] = 'application/javascript'
 # Without the correct MIME type, async compilation doesn't work
 Handler.extensions_map['.wasm'] = 'application/wasm'
 
-httpd = SocketServer.TCPServer(("", PORT), Handler)
+httpd = socketserver.TCPServer(("", PORT), Handler)
 
 httpd.serve_forever()
diff --git a/specs/web-img-decode/proposed/serve.py b/specs/web-img-decode/proposed/serve.py
index 36da146d18dd..a3e1f2687771 100644
--- a/specs/web-img-decode/proposed/serve.py
+++ b/specs/web-img-decode/proposed/serve.py
@@ -1,20 +1,21 @@
+#!/usr/bin/env python3
 # Copyright 2018 Google LLC
-
+#
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 
-import SimpleHTTPServer
-import SocketServer
+import http.server
+import socketserver
 
-PORT = 8005
+PORT = 8000
 
-class Handler(SimpleHTTPServer.SimpleHTTPRequestHandler):
+class Handler(http.server.SimpleHTTPRequestHandler):
     pass
 
 Handler.extensions_map['.js'] = 'application/javascript'
 # Without the correct MIME type, async compilation doesn't work
 Handler.extensions_map['.wasm'] = 'application/wasm'
 
-httpd = SocketServer.TCPServer(("", PORT), Handler)
+httpd = socketserver.TCPServer(("", PORT), Handler)
 
 httpd.serve_forever()