diff --git a/.github/workflows/build.yml b/.github/workflows/build.yml
deleted file mode 100644
index 854640b..0000000
--- a/.github/workflows/build.yml
+++ /dev/null
@@ -1,15 +0,0 @@
-name: Build spec
-
-on: [pull_request, push]
-
-jobs:
-  build:
-    runs-on: ubuntu-latest
-
-    steps:
-    - uses: actions/checkout@v3
-    - uses: ljharb/actions/node/install@main
-      name: 'nvm install lts/* && npm install'
-      with:
-        node-version: lts/*
-    - run: npm run build
diff --git a/.github/workflows/deploy.yml b/.github/workflows/deploy.yml
deleted file mode 100644
index 43206c8..0000000
--- a/.github/workflows/deploy.yml
+++ /dev/null
@@ -1,23 +0,0 @@
-name: Deploy gh-pages
-
-on:
-  push:
-    branches:
-      - main
-
-jobs:
-  deploy:
-    runs-on: ubuntu-latest
-
-    steps:
-    - uses: actions/checkout@v3
-    - uses: ljharb/actions/node/install@main
-      name: 'nvm install lts/* && npm install'
-      with:
-        node-version: lts/*
-    - run: npm run build
-    - uses: JamesIves/github-pages-deploy-action@v4.3.3
-      with:
-        branch: gh-pages
-        folder: build
-        clean: true
diff --git a/.github/workflows/publish-main.yml b/.github/workflows/publish-main.yml
new file mode 100644
index 0000000..b701bfd
--- /dev/null
+++ b/.github/workflows/publish-main.yml
@@ -0,0 +1,23 @@
+name: Publish
+
+on:
+  push:
+    branches: [main]
+
+jobs:
+  publish:
+    runs-on: ubuntu-latest
+    steps:
+    - uses: actions/checkout@v4
+    - name: '[node LTS] npm install'
+      uses: ljharb/actions/node/install@main
+      with:
+        node-version: lts/*
+    - run: npm run build
+    - name: Publish to gh-pages
+      uses: JamesIves/github-pages-deploy-action@v4.3.3
+      with:
+        branch: gh-pages
+        folder: build
+        clean-exclude: |
+          pr
diff --git a/.github/workflows/publish-pr.yml b/.github/workflows/publish-pr.yml
new file mode 100644
index 0000000..2ea79ba
--- /dev/null
+++ b/.github/workflows/publish-pr.yml
@@ -0,0 +1,80 @@
+name: Publish PR
+
+on:
+  workflow_run:
+    workflows: ['Render PR']
+    types: [completed]
+
+jobs:
+  publish:
+    runs-on: ubuntu-latest
+    if: >
+      ${{
+        !github.event.repository.fork &&
+        github.event.workflow_run.event == 'pull_request' &&
+        github.event.workflow_run.conclusion == 'success'
+      }}
+    steps:
+    - name: Print event info
+      uses: actions/github-script@v7
+      with:
+        script: 'console.log(${{ toJson(github.event) }});'
+    - name: Download zipball
+      uses: actions/github-script@v7
+      with:
+        script: |
+          const { owner, repo } = context.repo;
+          const { total_count, artifacts } = await github.actions.listWorkflowRunArtifacts({
+            owner,
+            repo,
+            run_id: ${{ github.event.workflow_run.id }},
+            name: 'result',
+          });
+          if (total_count !== 1) {
+            const summary = artifacts?.map(artifact => {
+              const { name, size_in_bytes, url } = artifact;
+              return { name, size_in_bytes, url };
+            });
+            const repr = value => JSON.stringify(value);
+            throw Error(`Expected 1 artifact, got ${total_count} ${repr(summary ?? [])}`);
+          }
+          const artifactData = {
+            owner,
+            repo,
+            artifact_id: artifacts[0].id,
+            archive_format: 'zip',
+          };
+          const download = await github.actions.downloadArtifact(artifactData);
+          const fs = require('fs');
+          fs.writeFileSync('${{ github.workspace }}/result.zip', Buffer.from(download.data));
+    - name: Provide result directory
+      run: rmdir -rf result && mkdir -p result
+    - run: unzip -o result.zip -d result
+    - run: ls result
+    - name: Extract PR number
+      id: extract-pr-number
+      run: |
+        cd result
+        awk -vok=1 \
+          '{ print; if(!match($0, /^[1-9][0-9]*$/)) ok=0; } END { exit !(NR==1 && ok); }' \
+          pr-number.txt
+        echo "number=$(cat pr-number.txt)" >> $GITHUB_OUTPUT
+        rm pr-number.txt
+    - name: Publish to gh-pages
+      uses: JamesIves/github-pages-deploy-action@v4.3.3
+      with:
+        branch: gh-pages
+        folder: result
+        target-folder: pr/${{ steps.extract-pr-number.outputs.number }}
+    - name: Determine gh-pages url
+      id: get-pages-url
+      run: |
+        gh_pages_url="https://$(printf '%s' "$GITHUB_REPOSITORY" \
+          | sed 's#/#.github.io/#; s#^tc39.github.io/#tc39.es/#')"
+        echo "url=$gh_pages_url" >> $GITHUB_OUTPUT
+    - name: Provide PR comment
+      uses: phulsechinmay/rewritable-pr-comment@v0.3.0
+      with:
+        GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
+        message: |
+          The rendered spec for this PR is available at ${{ steps.get-pages-url.outputs.url }}.
diff --git a/.github/workflows/render-pr.yml b/.github/workflows/render-pr.yml
new file mode 100644
index 0000000..cfd9431
--- /dev/null
+++ b/.github/workflows/render-pr.yml
@@ -0,0 +1,22 @@
+name: Render PR
+
+on: [pull_request]
+
+jobs:
+  render:
+    runs-on: ubuntu-latest
+    if: ${{ github.event.pull_request }}
+    steps:
+    - uses: actions/checkout@v4
+    - name: '[node LTS] npm install'
+      uses: ljharb/actions/node/install@main
+      with:
+        node-version: lts/*
+    - run: npm run build
+    - name: Save PR number
+      run: echo ${{ github.event.number }} > build/pr-number.txt
+    - uses: actions/upload-artifact@v4
+      if: ${{ !github.event.repository.fork }}
+      with:
+        name: result
+        path: build/