diff --git a/src/utils/bookmark.ts b/src/utils/bookmark.ts
new file mode 100644
index 0000000..125e752
--- /dev/null
+++ b/src/utils/bookmark.ts
@@ -0,0 +1,32 @@
+import { DefinedTool } from '@tools/defineTool';
+
+const bookmarkedToolsKey = 'bookmarkedTools';
+
+export function getBookmarkedTools(): string[] {
+  return localStorage.getItem(bookmarkedToolsKey)?.split(',') ?? [];
+}
+
+export function isBookmarked(tool: DefinedTool): boolean {
+  return getBookmarkedTools().some((path) => path === tool.path);
+}
+
+export function toggleBookmarked(tool: DefinedTool) {
+  if (isBookmarked(tool)) {
+    unbookmark(tool);
+  } else {
+    bookmark(tool);
+  }
+}
+
+function bookmark(tool: DefinedTool) {
+  localStorage.setItem(
+    bookmarkedToolsKey,
+    tool.path + localStorage.getItem(bookmarkedToolsKey)
+  );
+}
+
+function unbookmark(tool: DefinedTool) {
+  const bookmarked = localStorage.getItem(bookmarkedToolsKey)?.split(',') ?? [];
+  const unbookmarked = bookmarked.filter((path) => path != tool.path);
+  localStorage.setItem(bookmarkedToolsKey, unbookmarked.join(','));
+}