diff --git a/flow-libs/commander.js.flow b/flow-libs/commander.js.flow
index 7173bf7b008..a89fd6db25a 100644
--- a/flow-libs/commander.js.flow
+++ b/flow-libs/commander.js.flow
@@ -244,7 +244,7 @@ declare module 'commander' {
     [key: string]: any;
   }
 
-  declare class commander$Command {
+  declare export class commander$Command {
     constructor(name?: string): commander$Command;
 
     args: string[];
diff --git a/packages/dev/bundle-stats-cli/README.md b/packages/dev/bundle-stats-cli/README.md
new file mode 100644
index 00000000000..f7ee10a4279
--- /dev/null
+++ b/packages/dev/bundle-stats-cli/README.md
@@ -0,0 +1,4 @@
+# bundle-stats-cli
+
+- Run `yarn link` in `packages/dev/bundle-stats-cli`
+- Run `parcel-bundle-stats` in the project root, a `parcel-bundle-reports` directory will be created with the stats file inside
diff --git a/packages/dev/bundle-stats-cli/bin.js b/packages/dev/bundle-stats-cli/bin.js
new file mode 100755
index 00000000000..24263e2c0de
--- /dev/null
+++ b/packages/dev/bundle-stats-cli/bin.js
@@ -0,0 +1,12 @@
+#! /usr/bin/env node
+
+/* eslint-disable no-console */
+// @flow strict-local
+'use strict';
+
+// $FlowFixMe[untyped-import]
+require('@parcel/babel-register');
+
+const cli = require('./src/cli');
+
+cli.command.parse();
diff --git a/packages/dev/bundle-stats-cli/package.json b/packages/dev/bundle-stats-cli/package.json
new file mode 100644
index 00000000000..91a7eaa8470
--- /dev/null
+++ b/packages/dev/bundle-stats-cli/package.json
@@ -0,0 +1,25 @@
+{
+  "name": "@parcel/bundle-stats-cli",
+  "version": "2.9.3",
+  "private": true,
+  "main": "lib/cli.js",
+  "source": "src/cli.js",
+  "bin": {
+    "parcel-bundle-stats": "bin.js"
+  },
+  "engines": {
+    "node": ">= 12.0.0",
+    "parcel": "^2.9.3"
+  },
+  "dependencies": {
+    "@parcel/reporter-bundle-stats": "^2.9.3",
+    "@parcel/core": "^2.9.3",
+    "@parcel/utils": "^2.9.3",
+    "commander": "^7.0.0",
+    "parcel-query": "^2.9.3"
+  },
+  "devDependencies": {
+    "@parcel/babel-register": "^2.9.3",
+    "@parcel/types": "^2.9.3"
+  }
+}
diff --git a/packages/dev/bundle-stats-cli/src/cli.js b/packages/dev/bundle-stats-cli/src/cli.js
new file mode 100644
index 00000000000..c4deed1549c
--- /dev/null
+++ b/packages/dev/bundle-stats-cli/src/cli.js
@@ -0,0 +1,84 @@
+/* eslint-disable no-console, monorepo/no-internal-import */
+// @flow strict-local
+
+import type {PackagedBundle} from '@parcel/types';
+import type {ParcelOptions} from '@parcel/core/src/types';
+
+// $FlowFixMe[untyped-import]
+import {version} from '../package.json';
+
+import commander from 'commander';
+import fs from 'fs';
+import path from 'path';
+
+import {DefaultMap} from '@parcel/utils';
+
+import {loadGraphs} from 'parcel-query/src/index.js';
+import {getBundleStats} from '@parcel/reporter-bundle-stats/src/BundleStatsReporter';
+import {PackagedBundle as PackagedBundleClass} from '@parcel/core/src/public/Bundle';
+import type {commander$Command} from 'commander';
+
+function run({cacheDir, outDir}) {
+  // 1. load bundle graph and info via parcel~query
+  let {bundleGraph, bundleInfo} = loadGraphs(cacheDir);
+
+  if (bundleGraph == null) {
+    console.error('Bundle Graph could not be found');
+    process.exit(1);
+    throw new Error();
+  }
+
+  if (bundleInfo == null) {
+    console.error('Bundle Info could not be found');
+    process.exit(1);
+    throw new Error();
+  }
+
+  // 2. generate stats files for each target
+  fs.mkdirSync(outDir, {recursive: true});
+
+  let projectRoot = process.cwd();
+
+  // $FlowFixMe[unclear-type]
+  let parcelOptions: ParcelOptions = ({projectRoot}: any);
+
+  let bundlesByTarget: DefaultMap<
+    string /* target name */,
+    Array<PackagedBundle>,
+  > = new DefaultMap(() => []);
+  for (let bundle of bundleGraph.getBundles()) {
+    bundlesByTarget
+      .get(bundle.target.name)
+      .push(
+        PackagedBundleClass.getWithInfo(
+          bundle,
+          bundleGraph,
+          parcelOptions,
+          bundleInfo.get(bundle.id),
+        ),
+      );
+  }
+
+  for (let [targetName, bundles] of bundlesByTarget) {
+    fs.writeFileSync(
+      path.join(outDir, `${targetName}-stats.json`),
+      JSON.stringify(getBundleStats(bundles, parcelOptions), null, 2),
+    );
+  }
+}
+
+export const command: commander$Command = new commander.Command()
+  .version(version, '-V, --version')
+  .description('Generate a stats report for a Parcel build')
+  .option('-v, --verbose', 'Print verbose output')
+  .option(
+    '-c, --cache-dir <path>',
+    'Directory to the parcel cache',
+    '.parcel-cache',
+  )
+  .option(
+    '-o, --out-dir <path>',
+    'Directory to write the stats to',
+    'parcel-bundle-reports',
+  )
+  .action(run);
diff --git a/packages/reporters/bundle-stats/package.json b/packages/reporters/bundle-stats/package.json
new file mode 100644
index 00000000000..2e4f0cce3c8
--- /dev/null
+++ b/packages/reporters/bundle-stats/package.json
@@ -0,0 +1,24 @@
+{
+  "name": "@parcel/reporter-bundle-stats",
+  "version": "2.9.3",
+  "publishConfig": {
+    "access": "public"
+  },
+  "main": "lib/BundleStatsReporter.js",
+  "source": "src/BundleStatsReporter.js",
+  "bin": {
+    "parcel-bundle-stats": "bin.js"
+  },
+  "engines": {
+    "node": ">= 12.0.0",
+    "parcel": "^2.3.1"
+  },
+  "dependencies": {
+    "@parcel/core": "^2.9.3",
+    "@parcel/plugin": "^2.9.3",
+    "@parcel/utils": "^2.9.3"
+  },
+  "devDependencies": {
+    "@parcel/types": "^2.9.3"
+  }
+}
diff --git a/packages/reporters/bundle-stats/src/BundleStatsReporter.js b/packages/reporters/bundle-stats/src/BundleStatsReporter.js
new file mode 100644
index 00000000000..41af0b2b968
--- /dev/null
+++ b/packages/reporters/bundle-stats/src/BundleStatsReporter.js
@@ -0,0 +1,99 @@
+// @flow strict-local
+
+import type {PackagedBundle, PluginOptions} from '@parcel/types';
+
+import {Reporter} from '@parcel/plugin';
+import {DefaultMap} from '@parcel/utils';
+
+import assert from 'assert';
+import path from 'path';
+
+export type AssetStat = {|
+  size: number,
+  name: string,
+  bundles: Array<string>,
+|};
+
+export type BundleStat = {|
+  size: number,
+  id: string,
+  assets: Array<string>,
+|};
+
+export type BundleStats = {|
+  bundles: {[key: string]: BundleStat},
+  assets: {[key: string]: AssetStat},
+|};
+
+export default (new Reporter({
+  async report({event, options}) {
+    if (event.type !== 'buildSuccess') {
+      return;
+    }
+
+    let bundlesByTarget: DefaultMap<
+      string /* target name */,
+      Array<PackagedBundle>,
+    > = new DefaultMap(() => []);
+    for (let bundle of event.bundleGraph.getBundles()) {
+      bundlesByTarget.get(bundle.target.name).push(bundle);
+    }
+
+    let reportsDir = path.join(options.projectRoot, 'parcel-bundle-reports');
+    await options.outputFS.mkdirp(reportsDir);
+
+    await Promise.all(
+      [...bundlesByTarget.entries()].map(([targetName, bundles]) =>
+        options.outputFS.writeFile(
+          path.join(reportsDir, `${targetName}-stats.json`),
+          JSON.stringify(getBundleStats(bundles, options), null, 2),
+        ),
+      ),
+    );
+  },
+}): Reporter);
+
+export function getBundleStats(
+  bundles: Array<PackagedBundle>,
+  options: PluginOptions,
+): BundleStats {
+  let bundlesByName = new Map<string, BundleStat>();
+  let assetsById = new Map<string, AssetStat>();
+
+  // let seen = new Map();
+
+  for (let bundle of bundles) {
+    let bundleName = path.relative(options.projectRoot, bundle.filePath);
+
+    // If we've already seen this bundle, we can skip it... right?
+    if (bundlesByName.has(bundleName)) {
+      // Sanity check: this is the same bundle, right?
+      assert(bundlesByName.get(bundleName)?.size === bundle.stats.size);
+      continue;
+    }
+
+    let assets = [];
+    bundle.traverseAssets(({id, filePath, stats: {size}}) => {
+      assets.push(id);
+      let assetName = path.relative(options.projectRoot, filePath);
+      if (assetsById.has(id)) {
+        assert(assetsById.get(id)?.name === assetName);
+        assert(assetsById.get(id)?.size === size);
+        assetsById.get(id)?.bundles.push(bundleName);
+      } else {
+        assetsById.set(id, {name: assetName, size, bundles: [bundleName]});
+      }
+    });
+
+    bundlesByName.set(bundleName, {
+      id: bundle.id,
+      size: bundle.stats.size,
+      assets,
+    });
+  }
+
+  return {
+    bundles: Object.fromEntries(bundlesByName),
+    assets: Object.fromEntries(assetsById),
+  };
+}