diff --git a/src/flags.ts b/src/flags.ts
index 677118bed..1884b248f 100644
--- a/src/flags.ts
+++ b/src/flags.ts
@@ -67,6 +67,14 @@ type Flags = Record<Flag, boolean>;
 // Exposed for testing.
 export const flagsForParams = (stage: Stage, params: URLSearchParams) => {
   const enableFlags = new Set(params.getAll("flag"));
+  try {
+    localStorage
+      .getItem("flags")
+      ?.split(",")
+      ?.forEach((f) => enableFlags.add(f.trim()));
+  } catch (e) {
+    // Ignore if there are local storage security issues
+  }
   const allFlagsDefault = enableFlags.has("none")
     ? false
     : enableFlags.has("*")