diff --git a/.github/workflows/e2e.yml b/.github/workflows/e2e.yml
index b97686db49..fe590dd10c 100644
--- a/.github/workflows/e2e.yml
+++ b/.github/workflows/e2e.yml
@@ -15,6 +15,7 @@ on:
 
 permissions:
   contents: read
+  pull-requests: write
 
 env:
   # For PRs and MergeQueues, the target commit is used, and for push events, github.event.previous is used.
@@ -48,11 +49,26 @@ jobs:
         with:
           ref: ${{ env.targetHash }}
 
+      - name: Install dependencies
+        if: ${{ steps.cache-snapshot.outputs.cache-hit != 'true' }}
+        uses: cypress-io/github-action@v6
+        with:
+          # just perform install
+          runTests: false
+
+      - name: Build
+        if: ${{ steps.cache-snapshot.outputs.cache-hit != 'true' && github.event_name == 'pull_request' }}
+        run: |
+          pnpm run build:viz
+          mkdir -p cypress/snapshots/stats/base
+          mv stats cypress/snapshots/stats/base
+
       - name: Cypress run
-        uses: cypress-io/github-action@v4
+        uses: cypress-io/github-action@v6
         id: cypress-snapshot-gen
         if: ${{ steps.cache-snapshot.outputs.cache-hit != 'true' }}
         with:
+          install: false
           start: pnpm run dev
           wait-on: 'http://localhost:9000'
           browser: chrome
@@ -86,15 +102,42 @@ jobs:
           path: ./cypress/snapshots
           key: ${{ runner.os }}-snapshots-${{ env.targetHash }}
 
+      - name: Install dependencies
+        uses: cypress-io/github-action@v6
+        with:
+          runTests: false
+
+      - name: Build
+        id: size
+        if: ${{ github.event_name == 'pull_request' && matrix.containers == 1 }}
+        run: |
+          pnpm run build:viz
+          mv stats cypress/snapshots/stats/head
+          {
+            echo 'size_diff<<EOF'
+            npx tsx scripts/size.ts
+            echo EOF
+          } >> "$GITHUB_OUTPUT"
+
+      # Size diff only needs to be posted from one job, on PRs.
+      - name: Comment PR size difference
+        if: ${{ github.event_name == 'pull_request' && matrix.containers == 1 }}
+        uses: thollander/actions-comment-pull-request@v2
+        with:
+          message: |
+            ${{ steps.size.outputs.size_diff }}
+          comment_tag: size-diff
+
       # Install NPM dependencies, cache them correctly
       # and run all Cypress tests
       - name: Cypress run
-        uses: cypress-io/github-action@v4
+        uses: cypress-io/github-action@v6
         id: cypress
         # If CYPRESS_RECORD_KEY is set, run in parallel on all containers
         # Otherwise (e.g. if running from fork), we run on a single container only
         if: ${{ ( env.CYPRESS_RECORD_KEY != '' ) || ( matrix.containers == 1 ) }}
         with:
+          install: false
           start: pnpm run dev:coverage
           wait-on: 'http://localhost:9000'
           browser: chrome
diff --git a/package.json b/package.json
index a8ddc379ce..48e92bc238 100644
--- a/package.json
+++ b/package.json
@@ -111,6 +111,7 @@
     "jsdom": "^22.0.0",
     "langium-cli": "3.0.1",
     "lint-staged": "^13.2.1",
+    "markdown-table": "^3.0.3",
     "nyc": "^15.1.0",
     "path-browserify": "^1.0.1",
     "pnpm": "^8.6.8",
diff --git a/pnpm-lock.yaml b/pnpm-lock.yaml
index bf104511b3..8b83ffdfd0 100644
--- a/pnpm-lock.yaml
+++ b/pnpm-lock.yaml
@@ -163,6 +163,9 @@ importers:
       lint-staged:
         specifier: ^13.2.1
         version: 13.3.0
+      markdown-table:
+        specifier: ^3.0.3
+        version: 3.0.3
       nyc:
         specifier: ^15.1.0
         version: 15.1.0
diff --git a/scripts/size.ts b/scripts/size.ts
new file mode 100644
index 0000000000..2190fd9ef2
--- /dev/null
+++ b/scripts/size.ts
@@ -0,0 +1,82 @@
+/* eslint-disable no-console */
+import type { Metafile } from 'esbuild';
+import { readFile } from 'fs/promises';
+import { globby } from 'globby';
+import { markdownTable } from 'markdown-table';
+export const getSizes = (metafile: Metafile) => {
+  const { outputs } = metafile;
+  const sizes = Object.keys(outputs)
+    .filter((key) => key.endsWith('js') && !key.includes('chunk'))
+    .map((key) => {
+      const { bytes } = outputs[key];
+      return [key.replace('dist/', ''), bytes];
+    });
+  return sizes;
+};
+
+const readStats = async (path: string): Promise<Record<string, number>> => {
+  const files = await globby(path);
+  const contents = await Promise.all(files.map((file) => readFile(file, 'utf-8')));
+  const sizes = contents.flatMap((content) => getSizes(JSON.parse(content)));
+  return Object.fromEntries(sizes);
+};
+
+const formatBytes = (bytes: number): string => {
+  if (bytes == 0) {
+    return '0 Bytes';
+  }
+  const base = 1024;
+  const decimals = 2;
+  const sizes = ['Bytes', 'KB', 'MB', 'GB', 'TB', 'PB', 'EB', 'ZB', 'YB'];
+  const i = Math.floor(Math.log(bytes) / Math.log(base));
+  return parseFloat((bytes / Math.pow(base, i)).toFixed(decimals)) + ' ' + sizes[i];
+};
+
+const formatSize = (bytes: number): string => {
+  const formatted = formatBytes(bytes);
+  if (formatted.includes('Bytes')) {
+    return formatted;
+  }
+  return `${formatBytes(bytes)} (${bytes} Bytes)`;
+};
+
+const percentageDifference = (oldValue: number, newValue: number): string => {
+  const difference = Math.abs(newValue - oldValue);
+  const avg = (newValue + oldValue) / 2;
+  const percentage = (difference / avg) * 100;
+  const roundedPercentage = percentage.toFixed(2); // Round to two decimal places
+  if (roundedPercentage === '0.00') {
+    return '0.00%';
+  }
+  const sign = newValue > oldValue ? '+' : '-';
+  return `${sign}${roundedPercentage}%`;
+};
+
+const main = async () => {
+  const oldStats = await readStats('./cypress/snapshots/stats/base/**/*.json');
+  const newStats = await readStats('./cypress/snapshots/stats/head/**/*.json');
+  const diff = Object.entries(newStats)
+    .filter(([, value]) => value > 2048)
+    .map(([key, value]) => {
+      const oldValue = oldStats[key];
+      const delta = value - oldValue;
+      const output = [
+        key,
+        formatSize(oldValue),
+        formatSize(value),
+        formatSize(delta),
+        percentageDifference(oldValue, value),
+      ];
+      return output;
+    })
+    .filter(([, , , delta]) => delta !== '0 Bytes');
+  if (diff.length === 0) {
+    console.log('No changes in bundle sizes');
+    return;
+  }
+  console.log(
+    markdownTable([['File', 'Previous Size', 'New Size', 'Difference', '% Change'], ...diff])
+  );
+};
+
+void main().catch((e) => console.error(e));