diff --git a/hub/mixins.py b/hub/mixins.py
index 5d7fb437b..aa3d5096a 100644
--- a/hub/mixins.py
+++ b/hub/mixins.py
@@ -24,6 +24,10 @@ class FilterMixin:
     def filters(self):
         filters = []
         for param, value in self.request.GET.items():
+            # we don't filter on blank values so skip them
+            if value == "":
+                continue
+
             if "__" in param and param not in ["shader", "columns"]:
                 name, comparator = param.split("__", 1)
             else:  # pragma: nocover
diff --git a/hub/static/js/explore.esm.js b/hub/static/js/explore.esm.js
index c26af472c..aba8a6cdc 100644
--- a/hub/static/js/explore.esm.js
+++ b/hub/static/js/explore.esm.js
@@ -245,9 +245,16 @@ const app = createApp({
 
       return url
     },
+    filtersValid() {
+      return this.filters.every(function(filter){
+        return filter.selectedValue !== "";
+      });
+    },
     updateState() {
-      window.history.replaceState(this.state(), '', this.url())
-      this.updateResults()
+      if (this.filtersValid()) {
+        window.history.replaceState(this.state(), '', this.url())
+        this.updateResults()
+      }
     },
     restoreState() {
       const params = new URL(window.location).searchParams
diff --git a/hub/templates/hub/explore.html b/hub/templates/hub/explore.html
index a5f35262c..31bcceece 100644
--- a/hub/templates/hub/explore.html
+++ b/hub/templates/hub/explore.html
@@ -47,11 +47,11 @@ <h3 class="h6">${ filter.title }</h3>
                             <option v-for="option in filter.options" :value="option">${ option }</option>
                         </select>
                         <div v-else-if="filter.data_type == 'percent'" class="input-group flex-grow-1 flex-shrink-1">
-                            <input type="text" inputmode="numeric" pattern="[0-9]*" v-model="filter.selectedValue" class="form-control form-control-sm text-end">
+                            <input type="text" inputmode="numeric" pattern="[0-9]*" v-model="filter.selectedValue" class="form-control form-control-sm text-end" :class="{ 'is-invalid': filter.selectedValue === '' }">
                             <span class="input-group-text lh-1">%</span>
                         </div>
-                        <input v-else-if="filter.data_type == 'integer'" type="text" inputmode="numeric" pattern="[0-9]*" v-model="filter.selectedValue" class="form-control form-control-sm flex-grow-1 flex-shrink-1">
-                        <input v-else type="text" v-model="filter.selectedValue" class="form-control form-control-sm flex-grow-1 flex-shrink-1">
+                        <input v-else-if="filter.data_type == 'integer'" type="text" inputmode="numeric" pattern="[0-9]*" v-model="filter.selectedValue" class="form-control form-control-sm flex-grow-1 flex-shrink-1" :class="{ 'is-invalid': filter.selectedValue === '' }">
+                        <input v-else type="text" v-model="filter.selectedValue" class="form-control form-control-sm flex-grow-1 flex-shrink-1" :class="{ 'is-invalid': filter.selectedValue === '' }">
                         <p v-if="filter.is_in" class="flex-grow-1 text-muted mb-0 mt-2 text-center fs-8">Tip: Ctrl-click (PC) or Cmd-click (Mac) to select multiple items</p>
                     </div>
                     <details class="mt-3">
diff --git a/hub/tests/test_views.py b/hub/tests/test_views.py
index 59d4af201..5fcb4cf42 100644
--- a/hub/tests/test_views.py
+++ b/hub/tests/test_views.py
@@ -124,6 +124,14 @@ def setUp(self):
         self.u = User.objects.create(username="user@example.com")
         self.client.force_login(self.u)
 
+    def test_explore_json_page_null_value(self):
+        url = reverse("explore_json")
+        response = self.client.get(url + "?mp_last_elected__year__lt=")
+        self.assertEqual(response.status_code, 200)
+        self.assertContains(response, "South Borsetshire")
+        self.assertContains(response, "Borsetshire West")
+        self.assertContains(response, "Borsetshire East")
+
     def test_explore_json_page_year_lt(self):
         url = reverse("explore_json")
         response = self.client.get(url + "?mp_last_elected__year__lt=2019")