diff --git a/.github/workflows/NotebookDifference.yaml b/.github/workflows/NotebookDifference.yaml
new file mode 100644
index 00000000..b679fbbe
--- /dev/null
+++ b/.github/workflows/NotebookDifference.yaml
@@ -0,0 +1,56 @@
+name: Compare notebook files
+on:
+    # workflow_dispatch:
+    # push:
+    #     paths-ignore:
+    #         - "**.md"
+    #     branches:
+    #         - main
+    pull_request:
+        paths-ignore:
+            - "**.md"
+
+jobs:
+    notebook-changes-check:
+        runs-on: ubuntu-24.04
+        steps:
+            - name: Checkout
+              uses: actions/checkout@v4
+              with:
+                fetch-depth: 0
+                path: source
+
+
+            - name: Checkout
+              uses: actions/checkout@v4
+              with:
+                ref: dist
+                path: gh_pages_dir
+
+
+            - name: Install Julia
+              uses: julia-actions/setup-julia@v2
+              with:
+                  # note: this version should match the version in the other actions in this repo
+                  version: "1.11"
+
+            - name: Cache Julia artifacts & such
+              uses: julia-actions/cache@v2
+              with:
+                cache-registries: "true"
+
+            # We set up a folder that Pluto can use to cache exported notebooks. If the notebook file did not change, then Pluto can take the exported file from cache instead of running the notebook.
+            - name: Set up notebook state cache
+              uses: actions/cache@v4
+              with:
+                  path: pluto_state_cache
+                  # use the same key as the export action on the main branch:
+                  key: ${{ runner.os }}-pluto_state_cache-v3-${{ hashFiles('**/Project.toml', '**/Manifest.toml') }}-${{ github.run_id }}
+                  # here, you want to use the same restore key, but without the Project/Manifest hash:
+                  restore-keys: |
+                      ${{ runner.os }}-pluto_state_cache-v3
+
+            - name: Compare notebooks in PR
+              run: |
+                julia --threads=auto source/tools/diff.jl
+
diff --git a/pluto-deployment-environment/Manifest.toml b/pluto-deployment-environment/Manifest.toml
index e30e5649..0f1f0772 100644
--- a/pluto-deployment-environment/Manifest.toml
+++ b/pluto-deployment-environment/Manifest.toml
@@ -2,7 +2,7 @@
 
 julia_version = "1.11.3"
 manifest_format = "2.0"
-project_hash = "13a51ad2b377d764861ea553e631182e0e81a599"
+project_hash = "9854db52c26347aaaf320fc7b5e3c74d874b1bb3"
 
 [[deps.AbstractPlutoDingetjes]]
 deps = ["Pkg"]
@@ -354,6 +354,14 @@ git-tree-sha1 = "9071bfe6d1c3c51f62918513e8dfa0705fbdef7e"
 uuid = "72656b73-756c-7461-726b-72656b6b696b"
 version = "1.2.1"
 
+[[deps.PlutoNotebookComparison]]
+deps = ["Compat", "ExpressionExplorer", "HTTP", "InteractiveUtils", "LibGit2", "Logging", "LoggingExtras", "Markdown", "Pkg", "Pluto", "PlutoSliderServer", "TOML", "URIs"]
+git-tree-sha1 = "ad309f681e6f3812d943933ef736267911ebccc3"
+repo-rev = "main"
+repo-url = "https://github.com/JuliaPluto/PlutoNotebookComparison.jl"
+uuid = "828d9ff0-206c-6161-646e-6576656f7242"
+version = "1.0.0"
+
 [[deps.PlutoSliderServer]]
 deps = ["AbstractPlutoDingetjes", "Base64", "BetterFileWatching", "Configurations", "Distributed", "FromFile", "Git", "Glob", "HTTP", "JSON", "Logging", "Pkg", "Pluto", "PlutoDependencyExplorer", "SHA", "Serialization", "Sockets", "TOML", "TerminalLoggers", "UUIDs"]
 git-tree-sha1 = "9e1a630079de12343df2ccf9a90c46177bd38780"
diff --git a/pluto-deployment-environment/Project.toml b/pluto-deployment-environment/Project.toml
index ccd0eeae..f3f0f5f8 100644
--- a/pluto-deployment-environment/Project.toml
+++ b/pluto-deployment-environment/Project.toml
@@ -1,3 +1,4 @@
 [deps]
 Pluto = "c3e4b0f8-55cb-11ea-2926-15256bba5781"
+PlutoNotebookComparison = "828d9ff0-206c-6161-646e-6576656f7242"
 PlutoSliderServer = "2fc8631c-6f24-4c5b-bca7-cbb509c42db4"
diff --git a/tools/diff.jl b/tools/diff.jl
new file mode 100644
index 00000000..6ebabea0
--- /dev/null
+++ b/tools/diff.jl
@@ -0,0 +1,57 @@
+source = joinpath(@__DIR__, "..")
+
+
+function tryexpanduser(path)
+	try
+		expanduser(path)
+	catch ex
+		path
+	end
+end
+
+tamepath = abspath ∘ tryexpanduser
+
+pluto_state_cache = tamepath("pluto_state_cache")
+gh_pages_dir = tamepath("gh_pages_dir")
+
+if !isdir(pluto_state_cache) || readdir(pluto_state_cache) == []
+    @warn "Running this script without a GitHub Actions PlutoSliderServer cache. Using a local cache in the temp dir."
+    pluto_state_cache = joinpath(tempdir(), "bmlip cache")
+end
+
+cd(source)
+
+using Pkg
+Pkg.activate(joinpath(source, "pluto-deployment-environment"))
+Pkg.instantiate()
+
+using PlutoNotebookComparison
+
+
+sources_old = [
+    PSSCache(pluto_state_cache)
+    WebsiteDir(gh_pages_dir)
+    WebsiteAddress("https://featured.plutojl.org/")
+    SafePreview()
+]
+
+sources_new = [
+    PSSCache(pluto_state_cache)
+    RunWithPlutoSliderServer(; Export_cache_dir=pluto_state_cache)
+]
+
+drama_checkers = [
+    DramaRestartRequired()
+    DramaNewError()
+    DramaBrokenImport()
+]
+
+PlutoNotebookComparison.compare_PR(source;
+    sources_old,
+    sources_new,
+    drama_checkers,
+)
+
+
+
+
diff --git a/tools/update_notebook_packages.jl b/tools/update_notebook_packages.jl
index 9088c0f6..1a213f7b 100644
--- a/tools/update_notebook_packages.jl
+++ b/tools/update_notebook_packages.jl
@@ -29,8 +29,8 @@ all_notebooks = filter(Pluto.is_pluto_notebook, all_files_recursive)
 
 level = getfield(Pkg, Symbol("UPLEVEL_$(ARGS[1])"))
 
-for n in all_notebooks
-    @info "Updating" n
+for (i,n) in enumerate(all_notebooks)
+    @info "Updating [$i/$(length(all_notebooks))] $n"
     Pluto.update_notebook_environment(n; backup=false, level)
 end