diff --git a/.github/workflows/browser-package-size.yml b/.github/workflows/browser-package-size.yml
new file mode 100644
index 0000000000..293eb1c396
--- /dev/null
+++ b/.github/workflows/browser-package-size.yml
@@ -0,0 +1,14 @@
+name: sdk/browser/package-size
+
+on:
+  pull_request:
+    branches: [main, 'feat/**']
+    paths-ignore:
+      - '**.md'
+
+jobs:
+  package-size:
+    uses: launchdarkly/js-core/.github/workflows/package-size.yml@rlamb/sdk-167/bundle-size-report
+    with:
+      workspace_name: '@launchdarkly/js-client-sdk'
+      workspace_path: 'packages/sdk/browser'
diff --git a/.github/workflows/browser.yml b/.github/workflows/browser.yml
index da12b51e59..bfe0877917 100644
--- a/.github/workflows/browser.yml
+++ b/.github/workflows/browser.yml
@@ -31,3 +31,8 @@ jobs:
         with:
           workspace_name: '@launchdarkly/js-client-sdk'
           workspace_path: packages/sdk/browser
+  package-size:
+    uses: launchdarkly/js-core/.github/workflows/package-size.yml@rlamb/sdk-167/bundle-size-report
+    with:
+      workspace_name: '@launchdarkly/js-client-sdk'
+      workspace_path: 'packages/sdk/browser'
diff --git a/.github/workflows/package-size.yml b/.github/workflows/package-size.yml
new file mode 100644
index 0000000000..7931e159fc
--- /dev/null
+++ b/.github/workflows/package-size.yml
@@ -0,0 +1,34 @@
+name: Package size report.
+on:
+  workflow_call:
+    inputs:
+      workspace_name:
+        type: string
+        description: 'Name, from the package.json, of the package to build/test.'
+        required: true
+      workspace_path:
+        type: string
+        description: 'Path to the package to release.'
+        required: true
+
+permissions:
+  pull-requests: write
+jobs:
+  size:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v4
+
+      - uses: actions/setup-node@v4
+        with:
+          node-version: 21
+          registry-url: 'https://registry.npmjs.org'
+
+      - run: yarn workspaces focus ${{ inputs.workspace_name }}
+
+      - uses: andresz1/size-limit-action@v1
+        with:
+          directory: ${{ inputs.workspace_path }}
+          github_token: ${{ secrets.GITHUB_TOKEN }}
+          build_script: build-with-deps
+          skip_step: install
diff --git a/packages/sdk/browser/package.json b/packages/sdk/browser/package.json
index 8f66ed8d70..b4762cec93 100644
--- a/packages/sdk/browser/package.json
+++ b/packages/sdk/browser/package.json
@@ -48,6 +48,7 @@
   "scripts": {
     "clean": "rimraf dist",
     "build": "tsup",
+    "build-with-deps": "yarn workspaces foreach -pR --topological-dev --from '@launchdarkly/js-client-sdk' run build",
     "lint": "eslint . --ext .ts,.tsx",
     "prettier": "prettier --write '**/*.@(js|ts|tsx|json|css)' --ignore-path ../../../.prettierignore",
     "test": "npx jest --runInBand",
diff --git a/packages/shared/sdk-client/package.json b/packages/shared/sdk-client/package.json
index 28f75f9f02..8f909eba3d 100644
--- a/packages/shared/sdk-client/package.json
+++ b/packages/shared/sdk-client/package.json
@@ -35,6 +35,7 @@
     "make-esm-package-json": "echo '{\"type\":\"module\"}' > dist/esm/package.json",
     "make-package-jsons": "npm run make-cjs-package-json && npm run make-esm-package-json",
     "build": "npx tsc --noEmit && rollup -c rollup.config.js && npm run make-package-jsons",
+    "build-with-deps": "yarn workspaces foreach -pR --topological-dev --from '@launchdarkly/js-client-sdk-common' run build",
     "clean": "rimraf dist",
     "lint": "npx eslint . --ext .ts",
     "lint:fix": "yarn run lint -- --fix",