diff --git a/ui/src/Stores/AlertStore.js b/ui/src/Stores/AlertStore.js
index 7bd470fd6..f4ebb3568 100644
--- a/ui/src/Stores/AlertStore.js
+++ b/ui/src/Stores/AlertStore.js
@@ -285,13 +285,7 @@ class AlertStore {
 
     let updates = {};
     // update data dicts if they changed
-    for (const key of [
-      "colors",
-      "counters",
-      "groups",
-      "silences",
-      "upstreams"
-    ]) {
+    for (const key of ["colors", "counters", "silences", "upstreams"]) {
       if (!equal(this.data[key], result[key])) {
         updates[key] = result[key];
       }
@@ -300,6 +294,27 @@ class AlertStore {
       this.data = Object.assign(this.data, updates);
     }
 
+    // update groups, it can be huge so we have custom logic with cheaper
+    // comparision logic running per group using content hashes from the API
+    // response
+    for (const key of Object.keys(result.groups)) {
+      // set/update each group if:
+      // * it's not yet stored in AlertStore
+      // * it's stored but hash is different than in the API response
+      if (
+        !(key in this.data.groups) ||
+        (key in this.data.groups &&
+          result.groups[key].hash !== this.data.groups[key].hash)
+      ) {
+        this.data.groups[key] = result.groups[key];
+      }
+    }
+    for (const key of Object.keys(this.data.groups).filter(
+      k => !(k in result.groups)
+    )) {
+      delete this.data.groups[key];
+    }
+
     // before storing new version check if we need to reload
     if (
       this.info.version !== "unknown" &&
diff --git a/ui/src/Stores/AlertStore.test.js b/ui/src/Stores/AlertStore.test.js
index a9df5f260..2d692c927 100644
--- a/ui/src/Stores/AlertStore.test.js
+++ b/ui/src/Stores/AlertStore.test.js
@@ -333,4 +333,56 @@ describe("AlertStore.fetch", () => {
     await expect(store.fetch()).resolves.toBeUndefined();
     expect(store.info.upgradeNeeded).toBe(true);
   });
+
+  it("adds new groups to the store after fetch", () => {
+    const response = EmptyAPIResponse();
+    response.groups = { foo: "foo", bar: "bar" };
+    const store = new AlertStore(["label=value"]);
+    store.parseAPIResponse(response);
+    expect(Object.keys(store.data.groups)).toHaveLength(2);
+    expect(store.data.groups).toMatchObject({ foo: "foo", bar: "bar" });
+  });
+
+  it("is no-op for groups that didn't change", () => {
+    const store = new AlertStore(["label=value"]);
+    store.data.groups = { foo: { hash: "foo" }, bar: { hash: "bar" } };
+
+    const response = EmptyAPIResponse();
+    response.groups = { foo: { hash: "foo" }, bar: { hash: "bar" } };
+
+    store.parseAPIResponse(response);
+    expect(Object.keys(store.data.groups)).toHaveLength(2);
+    expect(store.data.groups).toMatchObject({
+      foo: { hash: "foo" },
+      bar: { hash: "bar" }
+    });
+  });
+
+  it("removes old groups from the store after fetch", () => {
+    const store = new AlertStore(["label=value"]);
+    store.data.groups = { foo: "foo", delete: "me", bar: "bar" };
+    expect(Object.keys(store.data.groups)).toHaveLength(3);
+
+    const response = EmptyAPIResponse();
+    response.groups = { foo: "foo", bar: "bar" };
+
+    store.parseAPIResponse(response);
+    expect(Object.keys(store.data.groups)).toHaveLength(2);
+    expect(store.data.groups).toMatchObject({ foo: "foo", bar: "bar" });
+  });
+
+  it("updates groups with new hash after fetch", () => {
+    const store = new AlertStore(["label=value"]);
+    store.data.groups = { foo: { hash: "foo" }, bar: { hash: "bar" } };
+
+    const response = EmptyAPIResponse();
+    response.groups = { foo: { hash: "newFoo" }, bar: { hash: "newBar" } };
+
+    store.parseAPIResponse(response);
+    expect(Object.keys(store.data.groups)).toHaveLength(2);
+    expect(store.data.groups).toMatchObject({
+      foo: { hash: "newFoo" },
+      bar: { hash: "newBar" }
+    });
+  });
 });