diff --git a/packages/extension/package.json b/packages/extension/package.json
index 877b28c96..4a93c285b 100644
--- a/packages/extension/package.json
+++ b/packages/extension/package.json
@@ -18,6 +18,7 @@
     "build": "yarn build:vite && yarn test:build",
     "build:dev": "yarn build:vite --mode development",
     "build:watch": "yarn build:dev --watch",
+    "build:browser": "OPEN_BROWSER=true yarn build:dev --watch",
     "build:vite": "vite build --configLoader runner --config vite.config.ts",
     "changelog:validate": "../../scripts/validate-changelog.sh @ocap/extension",
     "clean": "rimraf --glob './*.tsbuildinfo' ./.eslintcache ./coverage ./dist ./.turbo",
diff --git a/packages/extension/scripts/start.sh b/packages/extension/scripts/start.sh
index 9cbc2e272..644845168 100755
--- a/packages/extension/scripts/start.sh
+++ b/packages/extension/scripts/start.sh
@@ -23,4 +23,4 @@ function cleanup() {
 # Ensure we always close the ocap cli
 trap cleanup EXIT
 
-yarn build:watch
+yarn build:browser
diff --git a/packages/extension/vite.config.ts b/packages/extension/vite.config.ts
index 7ec408917..fc7482636 100644
--- a/packages/extension/vite.config.ts
+++ b/packages/extension/vite.config.ts
@@ -44,6 +44,7 @@ const staticCopyTargets: readonly (string | Target)[] = [
 export default defineConfig(({ mode }) => {
   const isDev = mode === 'development';
   const isWatching = process.argv.includes('--watch');
+  const shouldOpenBrowser = process.env.OPEN_BROWSER === 'true';
   if (isWatching && !isDev) {
     throw new Error('Cannot watch in non-development mode');
   }
@@ -111,8 +112,8 @@ export default defineConfig(({ mode }) => {
       }),
       moveHtmlFilesToRoot(),
       watchInternalPackages({ rootDir, packages: ['kernel-ui'] }),
-      // Open the extension in the browser when watching
-      isWatching && extensionDev({ extensionPath: outDir }),
+      // Open the extension in the browser when --browser flag is passed
+      shouldOpenBrowser && extensionDev({ extensionPath: outDir }),
     ],
   };
 });
diff --git a/packages/omnium-gatherum/package.json b/packages/omnium-gatherum/package.json
index 42ab27861..fca01cab9 100644
--- a/packages/omnium-gatherum/package.json
+++ b/packages/omnium-gatherum/package.json
@@ -19,6 +19,7 @@
     "build": "yarn build:vite && yarn test:build",
     "build:dev": "yarn build:vite --mode development",
     "build:watch": "yarn build:dev --watch",
+    "build:browser": "OPEN_BROWSER=true yarn build:dev --watch",
     "build:vite": "vite build --configLoader runner --config vite.config.ts",
     "changelog:validate": "../../scripts/validate-changelog.sh @ocap/omnium-gatherum",
     "clean": "rimraf --glob './*.tsbuildinfo' ./.eslintcache ./coverage ./dist ./.turbo",
diff --git a/packages/omnium-gatherum/scripts/start.sh b/packages/omnium-gatherum/scripts/start.sh
index 9cbc2e272..644845168 100755
--- a/packages/omnium-gatherum/scripts/start.sh
+++ b/packages/omnium-gatherum/scripts/start.sh
@@ -23,4 +23,4 @@ function cleanup() {
 # Ensure we always close the ocap cli
 trap cleanup EXIT
 
-yarn build:watch
+yarn build:browser
diff --git a/packages/omnium-gatherum/vite.config.ts b/packages/omnium-gatherum/vite.config.ts
index 2313eae62..1caf51ceb 100644
--- a/packages/omnium-gatherum/vite.config.ts
+++ b/packages/omnium-gatherum/vite.config.ts
@@ -52,6 +52,7 @@ const trustedPreludes: PreludeRecord = {
 export default defineConfig(({ mode }) => {
   const isDev = mode === 'development';
   const isWatching = process.argv.includes('--watch');
+  const shouldOpenBrowser = process.env.OPEN_BROWSER === 'true';
   if (isWatching && !isDev) {
     throw new Error('Cannot watch in non-development mode');
   }
@@ -121,8 +122,8 @@ export default defineConfig(({ mode }) => {
       }),
       moveHtmlFilesToRoot(),
       watchInternalPackages({ rootDir, packages: ['kernel-ui'] }),
-      // Open the extension in the browser when watching
-      isWatching && extensionDev({ extensionPath: outDir }),
+      // Open the extension in the browser when --browser flag is passed
+      shouldOpenBrowser && extensionDev({ extensionPath: outDir }),
     ],
   };
 });
diff --git a/packages/repo-tools/src/vite-plugins/extension-dev.ts b/packages/repo-tools/src/vite-plugins/extension-dev.ts
index a4cb7c3e1..de10ef4c8 100644
--- a/packages/repo-tools/src/vite-plugins/extension-dev.ts
+++ b/packages/repo-tools/src/vite-plugins/extension-dev.ts
@@ -62,6 +62,7 @@ export function extensionDev({
       args: [
         `--disable-extensions-except=${extensionPath}`,
         `--load-extension=${extensionPath}`,
+        '--start-maximized',
       ],
     });
 
@@ -89,7 +90,6 @@ export function extensionDev({
 
     // Open the extensions page for our extension
     const extensionsPage = await browserContext.newPage();
-    await extensionsPage.setViewportSize({ width: 1300, height: 700 });
     await extensionsPage.goto(`chrome://extensions/?id=${extensionId}`);
 
     // Update state after all checks