diff --git a/e2e/tests/manifest-content.test.ts b/e2e/tests/manifest-content.test.ts
index 8720966b..e344d07d 100644
--- a/e2e/tests/manifest-content.test.ts
+++ b/e2e/tests/manifest-content.test.ts
@@ -194,15 +194,15 @@ describe('Manifest Content', () => {
   });
 
   describe('content_scripts', () => {
-    it('should group content scripts and styles together based on their matches and run_at', async () => {
+    it('should group content scripts and styles together based on their manifest properties', async () => {
       const project = new TestProject();
       project.addFile(
         'entrypoints/one.content/index.ts',
         `import "./style.css";
-      export default defineContentScript({
-        matches: ["*://google.com/*"],
-        main: () => {},
-      })`,
+        export default defineContentScript({
+          matches: ["*://google.com/*"],
+          main: () => {},
+        })`,
       );
       project.addFile(
         'entrypoints/one.content/style.css',
@@ -211,11 +211,11 @@ describe('Manifest Content', () => {
       project.addFile(
         'entrypoints/two.content/index.ts',
         `import "./style.css";
-      export default defineContentScript({
-        matches: ["*://google.com/*"],
-        runAt: "document_end",
-        main: () => {},
-      })`,
+        export default defineContentScript({
+          matches: ["*://google.com/*"],
+          runAt: "document_end",
+          main: () => {},
+        })`,
       );
       project.addFile(
         'entrypoints/two.content/style.css',
@@ -224,11 +224,11 @@ describe('Manifest Content', () => {
       project.addFile(
         'entrypoints/three.content/index.ts',
         `import "./style.css";
-      export default defineContentScript({
-        matches: ["*://google.com/*"],
-        runAt: "document_end",
-        main: () => {},
-      })`,
+        export default defineContentScript({
+          matches: ["*://google.com/*"],
+          runAt: "document_end",
+          main: () => {},
+        })`,
       );
       project.addFile(
         'entrypoints/three.content/style.css',
@@ -237,11 +237,11 @@ describe('Manifest Content', () => {
       project.addFile(
         'entrypoints/four.content/index.ts',
         `import "./style.css";
-      export default defineContentScript({
-        matches: ["*://duckduckgo.com/*"],
-        runAt: "document_end",
-        main: () => {},
-      })`,
+        export default defineContentScript({
+          matches: ["*://duckduckgo.com/*"],
+          runAt: "document_end",
+          main: () => {},
+        })`,
       );
       project.addFile(
         'entrypoints/four.content/style.css',
@@ -276,15 +276,15 @@ describe('Manifest Content', () => {
       project.addFile(
         'entrypoints/one.content/index.ts',
         `export default defineContentScript({
-        matches: ["*://google.com/*"],
-        main: () => {},
-      })`,
+          matches: ["*://google.com/*"],
+          main: () => {},
+        })`,
       );
       project.addFile(
         'entrypoints/two.content/style.css',
         `body {
-        background-color: red;
-      }`,
+          background-color: red;
+        }`,
       );
       project.setConfigFileConfig({
         manifest: {
diff --git a/src/core/types/external.ts b/src/core/types/external.ts
index 9caf0e4a..6c761b31 100644
--- a/src/core/types/external.ts
+++ b/src/core/types/external.ts
@@ -416,6 +416,8 @@ export interface ContentScriptDefinition extends ExcludableEntrypoint {
    * - `"manual"` - Exclude the CSS from the manifest. You are responsible for manually loading it
    *   onto the page. Use `browser.runtime.getURL("content-scripts/<name>.css")` to get the file's
    *   URL
+   * - `"ui"` - Exclude the CSS from the manifest. CSS will be automatically added to your UI when
+   *   calling `createContentScriptUi`
    *
    * @default "manifest"
    */
diff --git a/src/core/utils/__tests__/content-scripts.test.ts b/src/core/utils/__tests__/content-scripts.test.ts
index 0732a7a6..125d0ff1 100644
--- a/src/core/utils/__tests__/content-scripts.test.ts
+++ b/src/core/utils/__tests__/content-scripts.test.ts
@@ -1,26 +1,36 @@
 import { describe, expect, it } from 'vitest';
 import { hashContentScriptOptions } from '../content-scripts';
+import { fakeInternalConfig } from '../../../testing/fake-objects';
 
 describe('Content Script Utils', () => {
   describe('hashContentScriptOptions', () => {
     it('should return a string containing all the options with defaults applied', () => {
-      const hash = hashContentScriptOptions({ matches: [] });
+      const hash = hashContentScriptOptions(
+        { matches: [] },
+        fakeInternalConfig(),
+      );
 
       expect(hash).toMatchInlineSnapshot(
-        '"[[\\"allFrames\\",false],[\\"excludeGlobs\\",[]],[\\"excludeMatches\\",[]],[\\"includeGlobs\\",[]],[\\"matchAboutBlank\\",false],[\\"matches\\",[]],[\\"matchOriginAsFallback\\",false],[\\"runAt\\",\\"document_idle\\"],[\\"world\\",\\"ISOLATED\\"]]"',
+        '"[[\\"all_frames\\",false],[\\"exclude_globs\\",[]],[\\"exclude_matches\\",[]],[\\"include_globs\\",[]],[\\"match_about_blank\\",false],[\\"match_origin_as_fallback\\",false],[\\"matches\\",[]],[\\"run_at\\",\\"document_idle\\"],[\\"world\\",\\"ISOLATED\\"]]"',
       );
     });
 
     it('should be consistent regardless of the object ordering and default values', () => {
-      const hash1 = hashContentScriptOptions({
-        allFrames: true,
-        matches: ['*://google.com/*', '*://duckduckgo.com/*'],
-        matchAboutBlank: false,
-      });
-      const hash2 = hashContentScriptOptions({
-        matches: ['*://duckduckgo.com/*', '*://google.com/*'],
-        allFrames: true,
-      });
+      const hash1 = hashContentScriptOptions(
+        {
+          allFrames: true,
+          matches: ['*://google.com/*', '*://duckduckgo.com/*'],
+          matchAboutBlank: false,
+        },
+        fakeInternalConfig(),
+      );
+      const hash2 = hashContentScriptOptions(
+        {
+          matches: ['*://duckduckgo.com/*', '*://google.com/*'],
+          allFrames: true,
+        },
+        fakeInternalConfig(),
+      );
 
       expect(hash1).toBe(hash2);
     });
diff --git a/src/core/utils/content-scripts.ts b/src/core/utils/content-scripts.ts
index 2f31b124..7629761d 100644
--- a/src/core/utils/content-scripts.ts
+++ b/src/core/utils/content-scripts.ts
@@ -9,18 +9,27 @@ import { resolvePerBrowserOption } from './entrypoints';
  */
 export function hashContentScriptOptions(
   options: ContentScriptEntrypoint['options'],
+  config: InternalConfig,
 ): string {
-  const withDefaults: ContentScriptEntrypoint['options'] = {
-    excludeGlobs: [],
-    excludeMatches: [],
-    includeGlobs: [],
-    matchAboutBlank: false,
-    matchOriginAsFallback: false,
-    runAt: 'document_idle',
-    allFrames: false,
+  const simplifiedOptions = mapWxtOptionsToContentScript(options, config);
+
+  // Remove undefined fields and use defaults to generate hash
+  Object.keys(simplifiedOptions).forEach((key) => {
+    // @ts-expect-error: key not typed as keyof ...
+    if (simplifiedOptions[key] == null) delete simplifiedOptions[key];
+  });
+
+  const withDefaults: Manifest.ContentScript = {
+    exclude_globs: [],
+    exclude_matches: [],
+    include_globs: [],
+    match_about_blank: false,
+    run_at: 'document_idle',
+    all_frames: false,
+    // @ts-expect-error - not in type
+    match_origin_as_fallback: false,
     world: 'ISOLATED',
-    // TODO: strip undefined fields from options object to improve content script grouping.
-    ...options,
+    ...simplifiedOptions,
   };
   return JSON.stringify(
     Object.entries(withDefaults)
diff --git a/src/core/utils/manifest.ts b/src/core/utils/manifest.ts
index 0688d603..8463de04 100644
--- a/src/core/utils/manifest.ts
+++ b/src/core/utils/manifest.ts
@@ -314,7 +314,7 @@ function addEntrypoints(
       );
     } else {
       const hashToEntrypointsMap = contentScripts.reduce((map, script) => {
-        const hash = hashContentScriptOptions(script.options);
+        const hash = hashContentScriptOptions(script.options, config);
         if (map.has(hash)) map.get(hash)?.push(script);
         else map.set(hash, [script]);
         return map;