diff --git a/Libraries/LibWeb/IndexedDB/Internal/Algorithms.cpp b/Libraries/LibWeb/IndexedDB/Internal/Algorithms.cpp
index be3d860e750..42745cec306 100644
--- a/Libraries/LibWeb/IndexedDB/Internal/Algorithms.cpp
+++ b/Libraries/LibWeb/IndexedDB/Internal/Algorithms.cpp
@@ -1448,4 +1448,14 @@ WebIDL::ExceptionOr<GC::Ref<IDBKeyRange>> convert_a_value_to_a_key_range(JS::Rea
     return IDBKeyRange::create(realm, key, key, false, false);
 }
 
+// https://w3c.github.io/IndexedDB/#count-the-records-in-a-range
+JS::Value count_the_records_in_a_range(GC::Ref<ObjectStore> source, GC::Ref<IDBKeyRange> range)
+{
+    // 1. Let count be the number of records, if any, in source’s list of records with key in range.
+    auto count = source->count_records_in_range(range);
+
+    // 2. Return count.
+    return JS::Value(count);
+}
+
 }
diff --git a/Libraries/LibWeb/IndexedDB/Internal/Algorithms.h b/Libraries/LibWeb/IndexedDB/Internal/Algorithms.h
index 2bbb124fe65..12be59ff772 100644
--- a/Libraries/LibWeb/IndexedDB/Internal/Algorithms.h
+++ b/Libraries/LibWeb/IndexedDB/Internal/Algorithms.h
@@ -42,5 +42,6 @@ void inject_a_key_into_a_value_using_a_key_path(JS::Realm&, JS::Value, GC::Ref<K
 void delete_records_from_an_object_store(GC::Ref<ObjectStore>, GC::Ref<IDBKeyRange>);
 WebIDL::ExceptionOr<GC::Ptr<Key>> store_a_record_into_an_object_store(JS::Realm&, GC::Ref<ObjectStore>, JS::Value, GC::Ptr<Key>, bool);
 WebIDL::ExceptionOr<GC::Ref<IDBKeyRange>> convert_a_value_to_a_key_range(JS::Realm&, Optional<JS::Value>, bool = false);
+JS::Value count_the_records_in_a_range(GC::Ref<ObjectStore>, GC::Ref<IDBKeyRange>);
 
 }
diff --git a/Libraries/LibWeb/IndexedDB/Internal/ObjectStore.cpp b/Libraries/LibWeb/IndexedDB/Internal/ObjectStore.cpp
index 79825d59f28..20d54b67d38 100644
--- a/Libraries/LibWeb/IndexedDB/Internal/ObjectStore.cpp
+++ b/Libraries/LibWeb/IndexedDB/Internal/ObjectStore.cpp
@@ -67,4 +67,14 @@ void ObjectStore::store_a_record(Record const& record)
     });
 }
 
+u64 ObjectStore::count_records_in_range(GC::Ref<IDBKeyRange> range)
+{
+    u64 count = 0;
+    for (auto const& record : m_records) {
+        if (range->is_in_range(record.key))
+            ++count;
+    }
+    return count;
+}
+
 }
diff --git a/Libraries/LibWeb/IndexedDB/Internal/ObjectStore.h b/Libraries/LibWeb/IndexedDB/Internal/ObjectStore.h
index b8277a239eb..aab58c3d4f5 100644
--- a/Libraries/LibWeb/IndexedDB/Internal/ObjectStore.h
+++ b/Libraries/LibWeb/IndexedDB/Internal/ObjectStore.h
@@ -52,6 +52,7 @@ public:
     void remove_records_in_range(GC::Ref<IDBKeyRange> range);
     bool has_record_with_key(GC::Ref<Key> key);
     void store_a_record(Record const& record);
+    u64 count_records_in_range(GC::Ref<IDBKeyRange> range);
 
 protected:
     virtual void visit_edges(Visitor&) override;