diff --git a/.github/workflows/size-compare.yml b/.github/workflows/size-compare.yml
index 59ebf66608..b0b6a7881c 100644
--- a/.github/workflows/size-compare.yml
+++ b/.github/workflows/size-compare.yml
@@ -139,7 +139,8 @@ jobs:
             --head desktop-client=./head/web-stats.json \
             --head loot-core=./head/loot-core-stats.json \
             --head api=./head/api-stats.json \
-            --identifier combined > bundle-stats-comment.md
+            --identifier combined \
+            --format pr-body > bundle-stats-comment.md
       - name: Post combined bundle stats comment
         env:
           GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
@@ -148,4 +149,5 @@ jobs:
         run: |
           node packages/ci-actions/bin/update-bundle-stats-comment.mjs \
             --comment-file bundle-stats-comment.md \
-            --identifier '<!--- bundlestats-action-comment key:combined --->'
+            --identifier combined \
+            --target pr-body
diff --git a/packages/ci-actions/bin/bundle-stats-comment.mjs b/packages/ci-actions/bin/bundle-stats-comment.mjs
index 391ea33ed7..124ed3a812 100644
--- a/packages/ci-actions/bin/bundle-stats-comment.mjs
+++ b/packages/ci-actions/bin/bundle-stats-comment.mjs
@@ -174,6 +174,7 @@ function parseArgs(argv) {
   return {
     sections,
     identifier: getSingleValue(args, 'identifier') ?? 'bundle-stats',
+    format: getSingleValue(args, 'format') ?? 'pr-body',
   };
 }
 
@@ -463,6 +464,12 @@ const TOTAL_HEADERS = makeHeader([
   'Total bundle size',
   '% Changed',
 ]);
+const SUMMARY_HEADERS = makeHeader([
+  'Bundle',
+  'Files count',
+  'Total bundle size',
+  '% Changed',
+]);
 const TABLE_HEADERS = makeHeader(['Asset', 'File Size', '% Changed']);
 const CHUNK_TABLE_HEADERS = makeHeader(['File', 'Δ', 'Size']);
 
@@ -596,6 +603,24 @@ function printTotalAssetTable(statsDiff) {
   return `**Total**\n${TOTAL_HEADERS}\n${printAssetTableRow(statsDiff.total)}`;
 }
 
+function printSummaryTable(sections) {
+  if (sections.length === 0) {
+    return `${SUMMARY_HEADERS}\nNo bundle stats were generated.`;
+  }
+
+  const rows = sections.map(section => {
+    const total = section.statsDiff.total;
+    return [
+      section.name,
+      total.name,
+      toFileSizeDiffCell(total),
+      conditionalPercentage(total.diffPercentage),
+    ].join(' | ');
+  });
+
+  return `${SUMMARY_HEADERS}\n${rows.join('\n')}`;
+}
+
 function renderSection(title, statsDiff, chunkModuleDiff) {
   const { total, ...groups } = statsDiff;
   const parts = [`#### ${title}`, '', printTotalAssetTable({ total })];
@@ -615,8 +640,30 @@ function renderSection(title, statsDiff, chunkModuleDiff) {
   return parts.join('\n');
 }
 
+function renderSections(sections) {
+  return sections
+    .map(section =>
+      renderSection(section.name, section.statsDiff, section.chunkDiff),
+    )
+    .join('\n\n---\n\n');
+}
+
+function getIdentifierMarkers(key) {
+  const label = 'bundlestats-action-comment';
+  return {
+    start: `<!--- ${label} key:${key} start --->`,
+    end: `<!--- ${label} key:${key} end --->`,
+  };
+}
+
 async function main() {
   const args = parseArgs(process.argv);
+  const allowedFormats = new Set(['comment', 'pr-body']);
+  if (!allowedFormats.has(args.format)) {
+    throw new Error(
+      `Invalid format "${args.format}". Use "comment" or "pr-body".`,
+    );
+  }
 
   console.error(
     `[bundle-stats] Found ${args.sections.length} sections to process`,
@@ -654,22 +701,29 @@ async function main() {
     });
   }
 
-  const identifier = `<!--- bundlestats-action-comment key:${args.identifier} --->`;
+  const markers = getIdentifierMarkers(args.identifier);
+  const sectionsContent = renderSections(sections);
+  const summaryTable = printSummaryTable(sections);
 
-  const comment = [
+  const detailedBody = ['### Bundle Stats', '', sectionsContent].join('\n');
+
+  const commentBody = [markers.start, detailedBody, '', markers.end, ''].join(
+    '\n',
+  );
+
+  const prBody = [
+    markers.start,
     '### Bundle Stats',
     '',
-    sections
-      .map(section =>
-        renderSection(section.name, section.statsDiff, section.chunkDiff),
-      )
-      .join('\n\n---\n\n'),
+    summaryTable,
     '',
-    identifier,
+    `<details>\n<summary>View detailed bundle stats</summary>\n\n${sectionsContent}\n</details>`,
+    '',
+    markers.end,
     '',
   ].join('\n');
 
-  process.stdout.write(comment);
+  process.stdout.write(args.format === 'comment' ? commentBody : prBody);
 }
 
 main().catch(error => {
diff --git a/packages/ci-actions/bin/update-bundle-stats-comment.mjs b/packages/ci-actions/bin/update-bundle-stats-comment.mjs
index c835be6251..ea69903b33 100644
--- a/packages/ci-actions/bin/update-bundle-stats-comment.mjs
+++ b/packages/ci-actions/bin/update-bundle-stats-comment.mjs
@@ -18,6 +18,7 @@ function parseArgs(argv) {
   const args = {
     commentFile: null,
     identifier: null,
+    target: 'comment',
   };
 
   for (let i = 2; i < argv.length; i += 2) {
@@ -41,6 +42,9 @@ function parseArgs(argv) {
       case '--identifier':
         args.identifier = value;
         break;
+      case '--target':
+        args.target = value;
+        break;
       default:
         throw new Error(`Unknown argument "${key}".`);
     }
@@ -54,6 +58,12 @@ function parseArgs(argv) {
     throw new Error('Missing required argument "--identifier".');
   }
 
+  if (!['comment', 'pr-body'].includes(args.target)) {
+    throw new Error(
+      `Invalid value "${args.target}" for "--target". Use "comment" or "pr-body".`,
+    );
+  }
+
   return args;
 }
 
@@ -110,20 +120,120 @@ function isGitHubActionsBot(comment) {
   return comment.user?.login === 'github-actions[bot]';
 }
 
+function escapeRegExp(value) {
+  return value.replace(/[.*+?^${}()|[\]\\]/g, '\\$&');
+}
+
+function getIdentifierMarkers(identifier) {
+  if (identifier.includes('<!---')) {
+    return {
+      start: identifier,
+      end: null,
+    };
+  }
+
+  const label = 'bundlestats-action-comment';
+  return {
+    start: `<!--- ${label} key:${identifier} start --->`,
+    end: `<!--- ${label} key:${identifier} end --->`,
+  };
+}
+
+function upsertBlock(existingBody, block, markers) {
+  const body = existingBody ?? '';
+
+  if (markers.end) {
+    const pattern = new RegExp(
+      `${escapeRegExp(markers.start)}[\\s\\S]*?${escapeRegExp(markers.end)}`,
+      'm',
+    );
+
+    if (pattern.test(body)) {
+      return body.replace(pattern, block.trim());
+    }
+  }
+
+  if (body.trim().length === 0) {
+    return block.trim();
+  }
+
+  const separator = body.endsWith('\n') ? '\n' : '\n\n';
+  return `${body}${separator}${block.trim()}`;
+}
+
+async function updatePullRequestBody(
+  octokit,
+  owner,
+  repo,
+  pullNumber,
+  block,
+  markers,
+) {
+  const { data } = await octokit.rest.pulls.get({
+    owner,
+    repo,
+    pull_number: pullNumber,
+  });
+  const nextBody = upsertBlock(data.body ?? '', block, markers);
+
+  await octokit.rest.pulls.update({
+    owner,
+    repo,
+    pull_number: pullNumber,
+    body: nextBody,
+  });
+}
+
+async function deleteExistingComment(
+  octokit,
+  owner,
+  repo,
+  issueNumber,
+  markers,
+) {
+  const comments = await listComments(octokit, owner, repo, issueNumber);
+  const existingComment = comments.find(
+    comment =>
+      isGitHubActionsBot(comment) && comment.body?.includes(markers.start),
+  );
+
+  if (existingComment) {
+    await octokit.rest.issues.deleteComment({
+      owner,
+      repo,
+      comment_id: existingComment.id,
+    });
+  }
+}
+
 async function main() {
-  const { commentFile, identifier } = parseArgs(process.argv);
+  const { commentFile, identifier, target } = parseArgs(process.argv);
   const commentBody = await loadCommentBody(commentFile);
   const token = assertGitHubToken();
   const { owner, repo } = getRepoInfo();
   const issueNumber = getPullRequestNumber();
+  const markers = getIdentifierMarkers(identifier);
 
   const octokit = new Octokit({ auth: token });
 
-  const comments = await listComments(octokit, owner, repo, issueNumber);
+  if (target === 'pr-body') {
+    await updatePullRequestBody(
+      octokit,
+      owner,
+      repo,
+      issueNumber,
+      commentBody,
+      markers,
+    );
+    await deleteExistingComment(octokit, owner, repo, issueNumber, markers);
+    console.log('Updated pull request body with bundle stats.');
+    return;
+  }
 
+  const comments = await listComments(octokit, owner, repo, issueNumber);
   const existingComment = comments.find(
     comment =>
-      isGitHubActionsBot(comment) && comment.body?.includes(identifier),
+      isGitHubActionsBot(comment) && comment.body?.includes(markers.start),
   );
 
   if (existingComment) {
@@ -134,15 +244,16 @@ async function main() {
       body: commentBody,
     });
     console.log('Updated existing bundle stats comment.');
-  } else {
-    await octokit.rest.issues.createComment({
-      owner,
-      repo,
-      issue_number: issueNumber,
-      body: commentBody,
-    });
-    console.log('Created new bundle stats comment.');
+    return;
   }
+
+  await octokit.rest.issues.createComment({
+    owner,
+    repo,
+    issue_number: issueNumber,
+    body: commentBody,
+  });
+  console.log('Created new bundle stats comment.');
 }
 
 main().catch(error => {
diff --git a/upcoming-release-notes/6677.md b/upcoming-release-notes/6677.md
new file mode 100644
index 0000000000..e6a2df6e58
--- /dev/null
+++ b/upcoming-release-notes/6677.md
@@ -0,0 +1,6 @@
+---
+category: Maintenance
+authors: [matt-fidd]
+---
+
+Post bundle size comparison comment in the PR body instead