diff --git a/test/benchmarks.cc b/test/benchmarks.cc
index 07326735..1935f431 100644
--- a/test/benchmarks.cc
+++ b/test/benchmarks.cc
@@ -19,8 +19,27 @@ vector<string> language_names({
   "python",
 });
 
+size_t mean(const vector<size_t> &values) {
+  if (values.empty()) return 0;
+  double result = 0;
+  for (double value : values) {
+    result += value;
+  }
+  return result / values.size();
+}
+
+size_t min(const vector<size_t> &values) {
+  double result = 0;
+  for (double value : values) {
+    if (value < result || result == 0) result = value;
+  }
+  return result;
+}
+
 int main(int argc, char *arg[]) {
   map<string, vector<ExampleEntry>> example_entries_by_language_name;
+  vector<size_t> error_speeds;
+  vector<size_t> non_error_speeds;
 
   auto document = ts_document_new();
 
@@ -46,6 +65,11 @@ int main(int argc, char *arg[]) {
 
     for (auto &example : example_entries_by_language_name[language_name]) {
       if (file_name_filter && example.file_name != file_name_filter) continue;
+      if (example.input.size() < 256) continue;
+
+      ts_document_invalidate(document);
+      ts_document_set_input_string(document, "");
+      ts_document_parse(document);
 
       ts_document_invalidate(document);
       ts_document_set_input_string(document, example.input.c_str());
@@ -55,7 +79,9 @@ int main(int argc, char *arg[]) {
       clock_t end_time = clock();
       unsigned duration = (end_time - start_time) * 1000 / CLOCKS_PER_SEC;
       assert(!ts_node_has_error(ts_document_root_node(document)));
-      printf("  %-30s\t%u\n", example.file_name.c_str(), duration);
+      size_t speed = static_cast<double>(example.input.size()) / duration;
+      printf("  %-30s\t%u ms\t\t%lu bytes/ms\n", example.file_name.c_str(), duration, speed);
+      non_error_speeds.push_back(speed);
     }
 
     for (auto &other_language_name : language_names) {
@@ -63,6 +89,7 @@ int main(int argc, char *arg[]) {
 
       for (auto &example : example_entries_by_language_name[other_language_name]) {
         if (file_name_filter && example.file_name != file_name_filter) continue;
+        if (example.input.size() < 256) continue;
 
         ts_document_invalidate(document);
         ts_document_set_input_string(document, example.input.c_str());
@@ -71,12 +98,23 @@ int main(int argc, char *arg[]) {
         ts_document_parse(document);
         clock_t end_time = clock();
         unsigned duration = (end_time - start_time) * 1000 / CLOCKS_PER_SEC;
-        printf("  %-30s\t%u\n", example.file_name.c_str(), duration);
+        size_t speed = static_cast<double>(example.input.size()) / duration;
+        printf("  %-30s\t%u ms\t\t%lu bytes/ms\n", example.file_name.c_str(), duration, speed);
+        error_speeds.push_back(speed);
       }
     }
 
     puts("");
   }
 
+  puts("without errors:");
+  printf("  %-30s\t%lu bytes/ms\n", "average speed", mean(non_error_speeds));
+  printf("  %-30s\t%lu bytes/ms\n", "worst speed", min(non_error_speeds));
+  puts("");
+
+  puts("with errors:");
+  printf("  %-30s\t%lu bytes/ms\n", "average speed", mean(error_speeds));
+  printf("  %-30s\t%lu bytes/ms\n", "worst speed", min(error_speeds));
+
   return 0;
 }