diff --git a/frontend_tests/run-casper b/frontend_tests/run-casper
index d5a18dfd06..7544eb3ece 100755
--- a/frontend_tests/run-casper
+++ b/frontend_tests/run-casper
@@ -21,20 +21,27 @@ os.environ["PHANTOMJS_EXECUTABLE"] = os.path.join(ZULIP_PATH, "node_modules/.bin
 os.environ.pop("http_proxy", "")
 os.environ.pop("https_proxy", "")
 
-usage = """test-js-with-casper [options]
+usage = """
+
     test-js-with-casper # Run all test files
     test-js-with-casper 09-navigation.js # Run a single test file
     test-js-with-casper 09 # Run a single test file 09-navigation.js
     test-js-with-casper 01-login.js 03-narrow.js # Run a few test files
-    test-js-with-casper 01 03 # Run a few test files, 01-login.js and 03-narrow.js here"""
-parser = argparse.ArgumentParser(usage)
+    test-js-with-casper 01 03 # Run a few test files, 01-login.js and 03-narrow.js here
+
+    Using loops:
+
+        test-js-with-capser --loop 5 07 # run 5 loops of test 07
+---
+"""
+parser = argparse.ArgumentParser(usage=usage)
 
 parser.add_argument('--skip-flaky-tests', dest='skip_flaky',
                     action="store_true",
                     default=False, help='Skip flaky tests')
-parser.add_argument('--interactive', dest='interactive',
-                    action="store_true",
-                    default=False, help='Run tests interactively')
+parser.add_argument('--loop', dest='loop', nargs=1,
+                    action="store", type=int,
+                    default=None, help='Run tests in a loop.')
 parser.add_argument('--force', dest='force',
                     action="store_true",
                     default=False, help='Run tests despite possible problems.')
@@ -98,6 +105,16 @@ def run_tests(files: Iterable[str], external_host: str) -> None:
     if options.skip_flaky:
         test_files = [fn for fn in test_files if '10-admin' not in fn]
 
+    if options.loop:
+        loop_cnt = options.loop[0]
+        print('\n\nWe will use loop mode for these tests:\n')
+        for test_file in test_files:
+            print('    ' + os.path.basename(test_file))
+        print('\nnumber of loops: {}\n'.format(loop_cnt))
+        print()
+    else:
+        loop_cnt = None
+
     remote_debug = []  # type: List[str]
     if options.remote_debug:
         remote_debug = ["--remote-debugger-port=7777", "--remote-debugger-autorun=yes"]
@@ -121,6 +138,27 @@ def run_tests(files: Iterable[str], external_host: str) -> None:
                 return ret
         return 0
 
+    def run_loops(loop_cnt: int) -> None:
+        while True:
+            for trial in range(1, loop_cnt + 1):
+                print('\n\n\nSTARTING TRIAL {} / {}\n'.format(trial, loop_cnt))
+                ret = run_tests()
+                if ret == 0:
+                    print('`\n\nSUCCESS! trial #{}\n\n'.format(trial))
+                else:
+                    print('\n\nFAIL! trial #{}\n'.format(trial))
+                    break
+
+            while True:
+                response = input('Press "q" to quit or enter number of loops: ')
+                if response == 'q':
+                    return
+                try:
+                    loop_cnt = int(response)
+                    break
+                except ValueError:
+                    continue
+
     with test_server_running(options.force, external_host):
         # Important: do next things inside the `with` block, when Django
         #            will be pointing at the test database.
@@ -128,15 +166,10 @@ def run_tests(files: Iterable[str], external_host: str) -> None:
         subprocess.check_call('tools/setup/generate-test-credentials')
 
         # RUN THE TESTS!!!
-        if options.interactive:
-            response = input('Press Enter to run tests, "q" to quit: ')
-            ret = 1
-            while response != 'q':
-                ret = run_tests()
-                if ret != 0:
-                    response = input('Tests failed. Press Enter to re-run tests, "q" to quit: ')
+        if loop_cnt:
+            run_loops(loop_cnt)
+            ret = 0
         else:
-            ret = 1
             ret = run_tests()
 
     if ret != 0: