diff --git a/package.json b/package.json
index f8c0b617..3fedd2f9 100644
--- a/package.json
+++ b/package.json
@@ -27,6 +27,7 @@
   "devDependencies": {
     "@microsoft/api-extractor": "^7.3.9",
     "@types/jest": "^24.0.18",
+    "brotli": "^1.3.2",
     "chalk": "^2.4.2",
     "execa": "^2.0.4",
     "fs-extra": "^8.1.0",
diff --git a/scripts/build.js b/scripts/build.js
index 704ebdb0..0ade7371 100644
--- a/scripts/build.js
+++ b/scripts/build.js
@@ -19,6 +19,7 @@ const path = require('path')
 const zlib = require('zlib')
 const chalk = require('chalk')
 const execa = require('execa')
+const { compress } = require('brotli')
 const { targets, fuzzyMatchTarget } = require('./utils')
 
 const args = require('minimist')(process.argv.slice(2))
@@ -109,10 +110,12 @@ function checkSize(target) {
   if (fs.existsSync(esmProdBuild)) {
     const file = fs.readFileSync(esmProdBuild)
     const minSize = (file.length / 1024).toFixed(2) + 'kb'
-    const gzipped = zlib.gzipSync(file)
-    const gzipSize = (gzipped.length / 1024).toFixed(2) + 'kb'
+    const compressed = compress(file)
+    const compressedSize = (compressed.length / 1024).toFixed(2) + 'kb'
     console.log(
-      `${chalk.gray(chalk.bold(target))} min:${minSize} / gzip:${gzipSize}`
+      `${chalk.gray(
+        chalk.bold(target)
+      )} min:${minSize} / brotli:${compressedSize}`
     )
   }
 }
diff --git a/yarn.lock b/yarn.lock
index af69dc58..1d1f33af 100644
--- a/yarn.lock
+++ b/yarn.lock
@@ -1618,6 +1618,11 @@ balanced-match@^1.0.0:
   resolved "https://registry.yarnpkg.com/balanced-match/-/balanced-match-1.0.0.tgz#89b4d199ab2bee49de164ea02b89ce462d71b767"
   integrity sha1-ibTRmasr7kneFk6gK4nORi1xt2c=
 
+base64-js@^1.1.2:
+  version "1.3.1"
+  resolved "https://registry.yarnpkg.com/base64-js/-/base64-js-1.3.1.tgz#58ece8cb75dd07e71ed08c736abc5fac4dbf8df1"
+  integrity sha512-mLQ4i2QO1ytvGWFWmcngKO//JXAQueZvwEKtjgQFM4jIK0kU+ytMfplL8j+n5mspOfjHwoAg+9yhb7BwAHm36g==
+
 base@^0.11.1:
   version "0.11.2"
   resolved "https://registry.yarnpkg.com/base/-/base-0.11.2.tgz#7bde5ced145b6d551a90db87f83c558b4eb48a8f"
@@ -1684,6 +1689,13 @@ braces@^3.0.1:
   dependencies:
     fill-range "^7.0.1"
 
+brotli@^1.3.2:
+  version "1.3.2"
+  resolved "https://registry.yarnpkg.com/brotli/-/brotli-1.3.2.tgz#525a9cad4fcba96475d7d388f6aecb13eed52f46"
+  integrity sha1-UlqcrU/LqWR119OI9q7LE+7VL0Y=
+  dependencies:
+    base64-js "^1.1.2"
+
 browser-process-hrtime@^0.1.2:
   version "0.1.2"
   resolved "https://registry.yarnpkg.com/browser-process-hrtime/-/browser-process-hrtime-0.1.2.tgz#425d68a58d3447f02a04aa894187fce8af8b7b8e"