diff --git a/testing/web-platform/meta/MANIFEST.json b/testing/web-platform/meta/MANIFEST.json
index 1004e847898d..6387f1075d1b 100644
--- a/testing/web-platform/meta/MANIFEST.json
+++ b/testing/web-platform/meta/MANIFEST.json
@@ -287571,6 +287571,11 @@
      {}
     ]
    ],
+   "interfaces/navigation-timing.idl": [
+    [
+     {}
+    ]
+   ],
    "interfaces/netinfo.idl": [
     [
      {}
@@ -355037,9 +355042,9 @@
      {}
     ]
    ],
-   "navigation-timing/idlharness.html": [
+   "navigation-timing/idlharness.window.js": [
     [
-     "/navigation-timing/idlharness.html",
+     "/navigation-timing/idlharness.window.html",
      {}
     ]
    ],
@@ -591004,6 +591009,10 @@
    "378af7beb3cf20086cec84840286f5e2a33f850c",
    "support"
   ],
+  "interfaces/navigation-timing.idl": [
+   "c12830eb9f5f18eef60557f5a93ea68812f78193",
+   "support"
+  ],
   "interfaces/netinfo.idl": [
    "357a99c1a5cb73265ee63d1ab1a0e413c6ced458",
    "support"
@@ -594364,8 +594373,8 @@
    "c238360f8496b546e525941b994bb3022be0c7ae",
    "support"
   ],
-  "navigation-timing/idlharness.html": [
-   "7b09fdf79c4166eaf21bcf2f92973c80b2864f32",
+  "navigation-timing/idlharness.window.js": [
+   "ec4f468da89e8339cfb9c3261bcef577bc2fc094",
    "testharness"
   ],
   "navigation-timing/nav2_data_uri.html": [
diff --git a/testing/web-platform/tests/interfaces/navigation-timing.idl b/testing/web-platform/tests/interfaces/navigation-timing.idl
new file mode 100644
index 000000000000..59f29fbdcf91
--- /dev/null
+++ b/testing/web-platform/tests/interfaces/navigation-timing.idl
@@ -0,0 +1,67 @@
+// GENERATED CONTENT - DO NOT EDIT
+// Content of this file was automatically extracted from the
+// "Navigation Timing Level 2" spec.
+// See: https://w3c.github.io/navigation-timing/
+
+[Exposed=Window]
+interface PerformanceNavigationTiming : PerformanceResourceTiming {
+    readonly attribute DOMHighResTimeStamp unloadEventStart;
+    readonly attribute DOMHighResTimeStamp unloadEventEnd;
+    readonly attribute DOMHighResTimeStamp domInteractive;
+    readonly attribute DOMHighResTimeStamp domContentLoadedEventStart;
+    readonly attribute DOMHighResTimeStamp domContentLoadedEventEnd;
+    readonly attribute DOMHighResTimeStamp domComplete;
+    readonly attribute DOMHighResTimeStamp loadEventStart;
+    readonly attribute DOMHighResTimeStamp loadEventEnd;
+    readonly attribute NavigationType      type;
+    readonly attribute unsigned short      redirectCount;
+    [Default] object toJSON();
+};
+enum NavigationType {
+    "navigate",
+    "reload",
+    "back_forward",
+    "prerender"
+};
+[Exposed=Window]
+interface PerformanceTiming {
+    readonly attribute unsigned long long navigationStart;
+    readonly attribute unsigned long long unloadEventStart;
+    readonly attribute unsigned long long unloadEventEnd;
+    readonly attribute unsigned long long redirectStart;
+    readonly attribute unsigned long long redirectEnd;
+    readonly attribute unsigned long long fetchStart;
+    readonly attribute unsigned long long domainLookupStart;
+    readonly attribute unsigned long long domainLookupEnd;
+    readonly attribute unsigned long long connectStart;
+    readonly attribute unsigned long long connectEnd;
+    readonly attribute unsigned long long secureConnectionStart;
+    readonly attribute unsigned long long requestStart;
+    readonly attribute unsigned long long responseStart;
+    readonly attribute unsigned long long responseEnd;
+    readonly attribute unsigned long long domLoading;
+    readonly attribute unsigned long long domInteractive;
+    readonly attribute unsigned long long domContentLoadedEventStart;
+    readonly attribute unsigned long long domContentLoadedEventEnd;
+    readonly attribute unsigned long long domComplete;
+    readonly attribute unsigned long long loadEventStart;
+    readonly attribute unsigned long long loadEventEnd;
+    [Default] object toJSON();
+};
+[Exposed=Window]
+interface PerformanceNavigation {
+    const unsigned short TYPE_NAVIGATE = 0;
+    const unsigned short TYPE_RELOAD = 1;
+    const unsigned short TYPE_BACK_FORWARD = 2;
+    const unsigned short TYPE_RESERVED = 255;
+    readonly attribute unsigned short type;
+    readonly attribute unsigned short redirectCount;
+    [Default] object toJSON();
+};
+[Exposed=Window]
+partial interface Performance {
+    [SameObject]
+    readonly attribute PerformanceTiming     timing;
+    [SameObject]
+    readonly attribute PerformanceNavigation navigation;
+};
diff --git a/testing/web-platform/tests/navigation-timing/idlharness.html b/testing/web-platform/tests/navigation-timing/idlharness.html
deleted file mode 100644
index 6c2d488ddc0a..000000000000
--- a/testing/web-platform/tests/navigation-timing/idlharness.html
+++ /dev/null
@@ -1,147 +0,0 @@
-<!DOCTYPE html>
-<html>
-<head>
-<meta charset="utf-8">
-<title>Navigation Timing IDL tests</title>
-<link rel="author" title="W3C" href="http://www.w3.org/" />
-<link rel="help" href="http://www.w3.org/TR/navigation-timing/#sec-navigation-timing-interface"/>
-<link rel="help" href="http://www.w3.org/TR/navigation-timing/#sec-navigation-info-interface"/>
-<link rel="help" href="http://www.w3.org/TR/navigation-timing/#sec-window.performance-attribute"/>
-<script src="/resources/testharness.js"></script>
-<script src="/resources/testharnessreport.js"></script>
-<script src="/resources/WebIDLParser.js"></script>
-<script src="/resources/idlharness.js"></script>
-</head>
-<body>
-<h1>Navigation Timing IDL tests</h1>
-<div id="log"></div>
-
-<pre id='untested_idl' style='display:none'>
-typedef double DOMHighResTimeStamp;
-
-[Exposed=(Window,Worker)]
-interface Performance {
-};
-
-[Exposed=(Window,Worker)]
-interface PerformanceEntry {
-    readonly attribute DOMString           name;
-    readonly attribute DOMString           entryType;
-    readonly attribute DOMHighResTimeStamp startTime;
-    readonly attribute DOMHighResTimeStamp duration;
-    [Default] object toJSON();
-  };
-
-[Exposed=(Window,Worker)]
-interface PerformanceResourceTiming : PerformanceEntry {
-    readonly attribute DOMString           initiatorType;
-    readonly attribute DOMString           nextHopProtocol;
-    readonly attribute DOMHighResTimeStamp workerStart;
-    readonly attribute DOMHighResTimeStamp redirectStart;
-    readonly attribute DOMHighResTimeStamp redirectEnd;
-    readonly attribute DOMHighResTimeStamp fetchStart;
-    readonly attribute DOMHighResTimeStamp domainLookupStart;
-    readonly attribute DOMHighResTimeStamp domainLookupEnd;
-    readonly attribute DOMHighResTimeStamp connectStart;
-    readonly attribute DOMHighResTimeStamp connectEnd;
-    readonly attribute DOMHighResTimeStamp secureConnectionStart;
-    readonly attribute DOMHighResTimeStamp requestStart;
-    readonly attribute DOMHighResTimeStamp responseStart;
-    readonly attribute DOMHighResTimeStamp responseEnd;
-    readonly attribute unsigned long long  transferSize;
-    readonly attribute unsigned long long  encodedBodySize;
-    readonly attribute unsigned long long  decodedBodySize;
-    [Default] object toJSON();
-  };
-</pre>
-
-<pre id='idl'>
-
-[Exposed=Window]
-interface PerformanceNavigationTiming : PerformanceResourceTiming {
-        readonly        attribute DOMHighResTimeStamp unloadEventStart;
-        readonly        attribute DOMHighResTimeStamp unloadEventEnd;
-        readonly        attribute DOMHighResTimeStamp domInteractive;
-        readonly        attribute DOMHighResTimeStamp domContentLoadedEventStart;
-        readonly        attribute DOMHighResTimeStamp domContentLoadedEventEnd;
-        readonly        attribute DOMHighResTimeStamp domComplete;
-        readonly        attribute DOMHighResTimeStamp loadEventStart;
-        readonly        attribute DOMHighResTimeStamp loadEventEnd;
-        readonly        attribute NavigationType      type;
-        readonly        attribute unsigned short      redirectCount;
-        [Default] object toJSON();
-};
-
-enum NavigationType {
-  "navigate",
-  "reload",
-  "back_forward",
-  "prerender"
-};
-
-
-[Exposed=Window]
-interface PerformanceTiming {
-  readonly attribute unsigned long long navigationStart;
-  readonly attribute unsigned long long unloadEventStart;
-  readonly attribute unsigned long long unloadEventEnd;
-  readonly attribute unsigned long long redirectStart;
-  readonly attribute unsigned long long redirectEnd;
-  readonly attribute unsigned long long fetchStart;
-  readonly attribute unsigned long long domainLookupStart;
-  readonly attribute unsigned long long domainLookupEnd;
-  readonly attribute unsigned long long connectStart;
-  readonly attribute unsigned long long connectEnd;
-  readonly attribute unsigned long long secureConnectionStart;
-  readonly attribute unsigned long long requestStart;
-  readonly attribute unsigned long long responseStart;
-  readonly attribute unsigned long long responseEnd;
-  readonly attribute unsigned long long domLoading;
-  readonly attribute unsigned long long domInteractive;
-  readonly attribute unsigned long long domContentLoadedEventStart;
-  readonly attribute unsigned long long domContentLoadedEventEnd;
-  readonly attribute unsigned long long domComplete;
-  readonly attribute unsigned long long loadEventStart;
-  readonly attribute unsigned long long loadEventEnd;
-  [Default] object toJSON();
-};
-
-
-[Exposed=Window]
-interface PerformanceNavigation {
-  const unsigned short TYPE_NAVIGATE = 0;
-  const unsigned short TYPE_RELOAD = 1;
-  const unsigned short TYPE_BACK_FORWARD = 2;
-  const unsigned short TYPE_RESERVED = 255;
-  readonly attribute unsigned short type;
-  readonly attribute unsigned short redirectCount;
-  [Default] object toJSON();
-};
-
-
-// [Exposed=Window]
-partial interface Performance {
-  [SameObject]
-  readonly attribute PerformanceTiming timing;
-  [SameObject]
-  readonly attribute PerformanceNavigation navigation;
-};
-</pre>
-
-<script>
-(function() {
-  var idl_array = new IdlArray();
-
-  idl_array.add_untested_idls(document.getElementById("untested_idl").textContent);
-  idl_array.add_idls(document.getElementById("idl").textContent);
-
-  idl_array.add_objects({Performance: ["window.performance"],
-                         PerformanceNavigation: ["window.performance.navigation"],
-                         PerformanceTiming: ["window.performance.timing"],
-                         PerformanceNavigationTiming: ["window.performance.getEntriesByType('navigation')[0]"] });
-
-  idl_array.test();
-})();
-</script>
-</body>
-</html>
diff --git a/testing/web-platform/tests/navigation-timing/idlharness.window.js b/testing/web-platform/tests/navigation-timing/idlharness.window.js
new file mode 100644
index 000000000000..a782773e59f3
--- /dev/null
+++ b/testing/web-platform/tests/navigation-timing/idlharness.window.js
@@ -0,0 +1,22 @@
+// META: script=/resources/WebIDLParser.js
+// META: script=/resources/idlharness.js
+
+'use strict';
+
+// http://www.w3.org/TR/navigation-timing/
+
+idl_test(
+  ['navigation-timing'],
+  ['resource-timing', 'performance-timeline', 'hr-time', 'dom'],
+  idl_array => {
+    idl_array.add_objects({
+      Performance: ['performance'],
+      PerformanceNavigation: ['performance.navigation'],
+      PerformanceTiming: ['performance.timing'],
+      PerformanceNavigationTiming: [
+        'performance.getEntriesByType("navigation")[0]'
+      ]
+    });
+  },
+  'navigation-timing interfaces'
+);