diff --git a/src/browser/tests/animation/animation.html b/src/browser/tests/animation/animation.html
index 886ac0b8..1cfb768a 100644
--- a/src/browser/tests/animation/animation.html
+++ b/src/browser/tests/animation/animation.html
@@ -15,7 +15,7 @@
     a1.play();
     cb.push(a1.playState);
   });
-  testing.eventually(() => testing.expectEqual(['idle', 'running', 'finished', true], cb));
+  testing.onload(() => testing.expectEqual(['idle', 'running', 'finished', true], cb));
 </script>
 
 <!-- <script id=startTime>
@@ -39,7 +39,7 @@
   // onfinish callback should be scheduled and called asynchronously
   a3.onfinish = function() { calls.push('finish'); };
   a3.play();
-  testing.eventually(() => testing.expectEqual(['finish'], calls));
+  testing.onload(() => testing.expectEqual(['finish'], calls));
 </script>
 
 <script id=pause>
@@ -52,7 +52,7 @@
     a4.pause();
     cb4.push(a4.playState)
   });
-  testing.eventually(() => testing.expectEqual(['running', 'paused'], cb4));
+  testing.onload(() => testing.expectEqual(['running', 'paused'], cb4));
 </script>
 
 <script id=finish>
@@ -65,6 +65,6 @@
     cb5.push(a5.playState);
     a5.play();
   });
-  testing.eventually(() => testing.expectEqual(['idle', 'finished'], cb5));
+  testing.onload(() => testing.expectEqual(['idle', 'finished'], cb5));
 </script>
  -->
diff --git a/src/browser/tests/css/font_face_set.html b/src/browser/tests/css/font_face_set.html
index c0248a74..c430a15b 100644
--- a/src/browser/tests/css/font_face_set.html
+++ b/src/browser/tests/css/font_face_set.html
@@ -71,7 +71,7 @@
 
     document.fonts.load("italic bold 16px Roboto");
 
-    testing.eventually(() => {
+    testing.onload(() => {
       testing.expectEqual(true, loading);
       testing.expectEqual(true, loadingdone);
     });
diff --git a/src/browser/tests/css/stylesheet.html b/src/browser/tests/css/stylesheet.html
index af6ba4ef..13a54731 100644
--- a/src/browser/tests/css/stylesheet.html
+++ b/src/browser/tests/css/stylesheet.html
@@ -498,7 +498,7 @@
         testing.expectEqual('.async-test', sheet.cssRules[0].selectorText);
         replacedAsync = true;
     });
-    testing.eventually(() => testing.expectTrue(replacedAsync));
+    testing.onload(() => testing.expectTrue(replacedAsync));
 }
 </script>
 
diff --git a/src/browser/tests/document/write.html b/src/browser/tests/document/write.html
index d9659e81..25a9901c 100644
--- a/src/browser/tests/document/write.html
+++ b/src/browser/tests/document/write.html
@@ -131,7 +131,7 @@
     document.open();
   }, 5);
 
-  testing.eventually(() => {
+  testing.onload(() => {
     // The element should be gone now
     const afterOpen = document.getElementById('will_be_removed');
     testing.expectEqual(null, afterOpen);
diff --git a/src/browser/tests/element/html/event_listeners.html b/src/browser/tests/element/html/event_listeners.html
index 73b85631..76db1a01 100644
--- a/src/browser/tests/element/html/event_listeners.html
+++ b/src/browser/tests/element/html/event_listeners.html
@@ -532,6 +532,6 @@
     testing.expectEqual(true, result);
   });
 
-  testing.eventually(() => testing.expectEqual(true, asyncBlockDispatched));
+  testing.onload(() => testing.expectEqual(true, asyncBlockDispatched));
 }
 </script>
diff --git a/src/browser/tests/element/html/image.html b/src/browser/tests/element/html/image.html
index 8874bbfe..1e672a6f 100644
--- a/src/browser/tests/element/html/image.html
+++ b/src/browser/tests/element/html/image.html
@@ -139,7 +139,7 @@
     });
   });
 
-  testing.eventually(() => testing.expectEqual(true, result));
+  testing.onload(() => testing.expectEqual(true, result));
 }
 </script>
 
@@ -150,7 +150,7 @@
   const img = document.createElement("img");
   img.addEventListener("load", () => { fired = true; });
   document.body.appendChild(img);
-  testing.eventually(() => testing.expectEqual(false, fired));
+  testing.onload(() => testing.expectEqual(false, fired));
 }
 </script>
 
@@ -163,7 +163,7 @@
   document.body.appendChild(img);
   img.src = "https://cdn.lightpanda.io/website/assets/images/docs/hn.png";
 
-  testing.eventually(() => testing.expectEqual(true, result));
+  testing.onload(() => testing.expectEqual(true, result));
 }
 </script>
 
diff --git a/src/browser/tests/element/html/input.html b/src/browser/tests/element/html/input.html
index 2b8576b5..d021fac6 100644
--- a/src/browser/tests/element/html/input.html
+++ b/src/browser/tests/element/html/input.html
@@ -210,7 +210,7 @@
     });
     input.setSelectionRange(1, 4);
 
-    testing.eventually(() => {
+    testing.onload(() => {
       testing.expectEqual(5, eventCount);
       testing.expectEqual('selectionchange', lastEvent.type);
       testing.expectEqual(input, lastEvent.target);
@@ -247,7 +247,7 @@
 
     input.select();
 
-    testing.eventually(() => {
+    testing.onload(() => {
       testing.expectEqual(1, eventCount);
       testing.expectEqual('select', lastEvent.type);
       testing.expectEqual(input, lastEvent.target);
diff --git a/src/browser/tests/element/html/link.html b/src/browser/tests/element/html/link.html
index 40d45c2f..57d9e28b 100644
--- a/src/browser/tests/element/html/link.html
+++ b/src/browser/tests/element/html/link.html
@@ -54,7 +54,7 @@
   link.rel = 'stylesheet';
   link.addEventListener('load', () => { fired = true; });
   document.head.appendChild(link);
-  testing.eventually(() => testing.expectEqual(false, fired));
+  testing.onload(() => testing.expectEqual(false, fired));
 }
 </script>
 
@@ -66,7 +66,7 @@
   link.href = 'https://lightpanda.io/opensource-browser/15';
   link.addEventListener('load', () => { fired = true; });
   document.head.appendChild(link);
-  testing.eventually(() => testing.expectEqual(false, fired));
+  testing.onload(() => testing.expectEqual(false, fired));
 }
 </script>
 
@@ -81,7 +81,7 @@
   // then set href.
   link.href = 'https://lightpanda.io/opensource-browser/15';
 
-  testing.eventually(() => testing.expectEqual(true, result));
+  testing.onload(() => testing.expectEqual(true, result));
 }
 </script>
 
@@ -98,7 +98,7 @@
   });
 
 
-  testing.eventually(() => {
+  testing.onload(() => {
     results.forEach((r) => {
       testing.expectEqual(true, r);
     });
diff --git a/src/browser/tests/element/html/script/dynamic.html b/src/browser/tests/element/html/script/dynamic.html
index dcd0d403..a6a0179c 100644
--- a/src/browser/tests/element/html/script/dynamic.html
+++ b/src/browser/tests/element/html/script/dynamic.html
@@ -8,14 +8,14 @@
   script1.async = false;
   script1.src = "dynamic1.js";
   document.getElementsByTagName('head')[0].appendChild(script1);
-  testing.eventually(() => {
+  testing.onload(() => {
     testing.expectEqual(1, loaded1);
   });
 </script>
 
 <script id=no_double_execute>
   document.getElementsByTagName('head')[0].appendChild(script1);
-  testing.eventually(() => {
+  testing.onload(() => {
     testing.expectEqual(1, loaded1);
   });
 </script>
@@ -25,7 +25,7 @@
   const script2a = document.createElement('script');
   script2a.src = "dynamic2.js";
   document.getElementsByTagName('head')[0].appendChild(script2a);
-  testing.eventually(() => {
+  testing.onload(() => {
     testing.expectEqual(2, loaded2);
   });
 </script>
@@ -38,7 +38,7 @@
 </script>
 
 <script id=src_after_append>
-  testing.eventually(() => {
+  testing.onload(() => {
     testing.expectEqual(2, loaded2);
   });
 </script>
diff --git a/src/browser/tests/element/html/script/dynamic_inline.html b/src/browser/tests/element/html/script/dynamic_inline.html
index d5cb60f2..e06b4821 100644
--- a/src/browser/tests/element/html/script/dynamic_inline.html
+++ b/src/browser/tests/element/html/script/dynamic_inline.html
@@ -48,7 +48,7 @@
   s6.type = 'module';
   s6.textContent = 'window.module_executed = true;';
   document.head.appendChild(s6);
-  testing.eventually(() => {
+  testing.onload(() => {
     testing.expectTrue(window.module_executed);
   });
 </script>
diff --git a/src/browser/tests/element/html/script/script.html b/src/browser/tests/element/html/script/script.html
index 75547d40..4f826fe7 100644
--- a/src/browser/tests/element/html/script/script.html
+++ b/src/browser/tests/element/html/script/script.html
@@ -21,7 +21,7 @@
    testing.expectEqual(testing.BASE_URL + 'element/html/script/empty.js', s.src);
    document.head.appendChild(s);
 
-   testing.eventually(() => {
+   testing.onload(() => {
       testing.expectEqual(true, dom_load);
       testing.expectEqual(true, attribute_load);
    });
diff --git a/src/browser/tests/element/html/slot.html b/src/browser/tests/element/html/slot.html
index b3ee2a58..ac162817 100644
--- a/src/browser/tests/element/html/slot.html
+++ b/src/browser/tests/element/html/slot.html
@@ -427,7 +427,7 @@
     div.setAttribute('slot', 'content');
     host.appendChild(div);
 
-    testing.eventually(() => {
+    testing.onload(() => {
         testing.expectEqual(1, calls);
     });
 }
@@ -455,7 +455,7 @@
 
     div.setAttribute('slot', 'other');
 
-    testing.eventually(() => {
+    testing.onload(() => {
         testing.expectEqual(1, calls);
     });
 }
@@ -483,7 +483,7 @@
 
     div.remove();
 
-    testing.eventually(() => {
+    testing.onload(() => {
         testing.expectEqual(1, calls);
     });
 }
@@ -511,7 +511,7 @@
 
     div.slot = 'other';
 
-    testing.eventually(() => {
+    testing.onload(() => {
         testing.expectEqual(1, calls);
     });
 }
diff --git a/src/browser/tests/element/html/style.html b/src/browser/tests/element/html/style.html
index ee393846..5a5cb4be 100644
--- a/src/browser/tests/element/html/style.html
+++ b/src/browser/tests/element/html/style.html
@@ -128,7 +128,7 @@
     });
   });
 
-  testing.eventually(() => testing.expectEqual(true, result));
+  testing.onload(() => testing.expectEqual(true, result));
 }
 </script>
 
diff --git a/src/browser/tests/element/html/textarea.html b/src/browser/tests/element/html/textarea.html
index 1690a132..daf57149 100644
--- a/src/browser/tests/element/html/textarea.html
+++ b/src/browser/tests/element/html/textarea.html
@@ -256,7 +256,7 @@
 
     textarea.select();
 
-    testing.eventually(() => {
+    testing.onload(() => {
       testing.expectEqual(1, eventCount);
       testing.expectEqual('select', lastEvent.type);
       testing.expectEqual(textarea, lastEvent.target);
@@ -295,7 +295,7 @@
     });
     textarea.setSelectionRange(1, 4);
     
-    testing.eventually(() => {
+    testing.onload(() => {
       testing.expectEqual(5, eventCount);
       testing.expectEqual('selectionchange', lastEvent.type);
       testing.expectEqual(textarea, lastEvent.target);
diff --git a/src/browser/tests/event/abort_controller.html b/src/browser/tests/event/abort_controller.html
index 4a14aee4..c3f448d4 100644
--- a/src/browser/tests/event/abort_controller.html
+++ b/src/browser/tests/event/abort_controller.html
@@ -242,7 +242,7 @@
 
 <script id=abortsignal_timeout>
   var s3 = AbortSignal.timeout(10);
-  testing.eventually(() => {
+  testing.onload(() => {
     testing.expectEqual(true, s3.aborted);
     testing.expectEqual('TimeoutError', s3.reason);
     testing.expectError('Error: TimeoutError', () => {
diff --git a/src/browser/tests/event/message.html b/src/browser/tests/event/message.html
index 079f9c7a..ad1f0596 100644
--- a/src/browser/tests/event/message.html
+++ b/src/browser/tests/event/message.html
@@ -61,7 +61,7 @@
 
   window.postMessage('test data', '*');
 
-  testing.eventually(() => {
+  testing.onload(() => {
     testing.expectEqual('test data', receivedEvent.data);
     testing.expectEqual(window, receivedEvent.source);
     testing.expectEqual('message', receivedEvent.type);
@@ -81,7 +81,7 @@
   const testObj = { type: 'test', value: 123, nested: { key: 'value' } };
   window.postMessage(testObj, '*');
 
-  testing.eventually(() => {
+  testing.onload(() => {
     testing.expectEqual(testObj, receivedData);
   });
 }
@@ -111,7 +111,7 @@
 
   window.postMessage(42, '*');
 
-  testing.eventually(() => {
+  testing.onload(() => {
     testing.expectEqual(42, received);
   });
 }
@@ -129,7 +129,7 @@
   const arr = [1, 2, 3, 'test'];
   window.postMessage(arr, '*');
 
-  testing.eventually(() => {
+  testing.onload(() => {
     testing.expectEqual(arr, received);
   });
 }
@@ -146,7 +146,7 @@
 
   window.postMessage(null, '*');
 
-  testing.eventually(() => {
+  testing.onload(() => {
     testing.expectEqual(null, received);
   });
 }
@@ -163,7 +163,7 @@
 
   window.postMessage('test', '*');
 
-  testing.eventually(() => {
+  testing.onload(() => {
     testing.expectEqual('http://127.0.0.1:9582', receivedOrigin);
   });
 }
diff --git a/src/browser/tests/event/message_multiple_listeners.html b/src/browser/tests/event/message_multiple_listeners.html
index 36f13eb2..ba5f408b 100644
--- a/src/browser/tests/event/message_multiple_listeners.html
+++ b/src/browser/tests/event/message_multiple_listeners.html
@@ -12,7 +12,7 @@
 
   window.postMessage('trigger', '*');
 
-  testing.eventually(() => {
+  testing.onload(() => {
     testing.expectEqual(2, count);
   });
 }
diff --git a/src/browser/tests/frames/frames.html b/src/browser/tests/frames/frames.html
index 7f9b636c..6634ccf2 100644
--- a/src/browser/tests/frames/frames.html
+++ b/src/browser/tests/frames/frames.html
@@ -28,7 +28,7 @@
   $('#f2').src = 'support/sub2.html';
   testing.expectEqual(true, true);
 
-  testing.eventually(() => {
+  testing.onload(() => {
     testing.expectEqual(undefined, window[20]);
 
     testing.expectEqual(window, window[1].top);
@@ -84,7 +84,7 @@
     f3.src = 'invalid'; // still fires load!
     document.documentElement.appendChild(f3);
 
-    testing.eventually(() => {
+    testing.onload(() => {
       testing.expectEqual('f1_onload_loaded', window.f1_onload);
       testing.expectEqual(true, f3_load_event);
     });
@@ -98,7 +98,7 @@
     f4.src = "about:blank";
     document.documentElement.appendChild(f4);
 
-    testing.eventually(() => {
+    testing.onload(() => {
       testing.expectEqual("<html><head></head><body></body></html>", f4.contentDocument.documentElement.outerHTML);
     });
   }
@@ -112,7 +112,7 @@
     document.documentElement.appendChild(f5);
     f5.src = "about:blank";
 
-    testing.eventually(() => {
+    testing.onload(() => {
       testing.expectEqual("<html><head></head><body></body></html>", f5.contentDocument.documentElement.outerHTML);
     });
   }
@@ -144,14 +144,14 @@
     let i = document.createElement('iframe');
     document.documentElement.appendChild(i);
     i.contentWindow.location.href = 'support/page.html';
-    testing.eventually(() => {
+    testing.onload(() => {
       testing.expectEqual('<html><head></head><body>a-page\n</body></html>', i.contentDocument.documentElement.outerHTML);
     });
   }
 </script>
 
 <script id=count>
-  testing.eventually(() => {
+  testing.onload(() => {
     testing.expectEqual(9, window.length);
   });
 </script>
diff --git a/src/browser/tests/frames/post_message.html b/src/browser/tests/frames/post_message.html
index 6d206b74..837897c3 100644
--- a/src/browser/tests/frames/post_message.html
+++ b/src/browser/tests/frames/post_message.html
@@ -17,7 +17,7 @@
     iframe.contentWindow.postMessage('ping', '*');
   });
 
-  testing.eventually(() => {
+  testing.onload(() => {
     testing.expectEqual('pong', reply.data);
     testing.expectEqual(testing.ORIGIN, reply.origin);
   });
diff --git a/src/browser/tests/frames/target.html b/src/browser/tests/frames/target.html
index 3c4c7f36..86e095e5 100644
--- a/src/browser/tests/frames/target.html
+++ b/src/browser/tests/frames/target.html
@@ -5,7 +5,7 @@
 <a id=l1 target=f1 href=support/page.html></a>
 <script id=anchor>
   $('#l1').click();
-  testing.eventually(() => {
+  testing.onload(() => {
     testing.expectEqual('<html><head></head><body>a-page\n</body></html>', $('#frame1').contentDocument.documentElement.outerHTML);
   });
 </script>
@@ -21,7 +21,7 @@
     form.action = 'support/page.html';
     form.submit();
 
-    testing.eventually(() => {
+    testing.onload(() => {
       testing.expectEqual('<html><head></head><body>a-page\n</body></html>', frame2.contentDocument.documentElement.outerHTML);
     });
   }
@@ -35,7 +35,7 @@
 <script id=formtarget>
   {
     $('#submit1').click();
-    testing.eventually(() => {
+    testing.onload(() => {
       testing.expectEqual('<html><head></head><body>a-page\n</body></html>', $('#f3').contentDocument.documentElement.outerHTML);
     });
   }
diff --git a/src/browser/tests/history.html b/src/browser/tests/history.html
index e2aa0d35..6380a6d2 100644
--- a/src/browser/tests/history.html
+++ b/src/browser/tests/history.html
@@ -8,7 +8,7 @@
   // If support/history.html has a failed assertion, it'll log the error and
   // stop the script. If it succeeds, it'll set support_history_completed
   // which we can use here to assume everything passed.
-  testing.eventually(() => {
+  testing.onload(() => {
     testing.expectEqual(true, window.support_history_completed);
     testing.expectEqual(true, window.support_history_popstateEventFired);
     testing.expectEqual({testInProgress: true }, window.support_history_popstateEventState);
diff --git a/src/browser/tests/intersection_observer/basic.html b/src/browser/tests/intersection_observer/basic.html
index 3c9258bf..8c6f3295 100644
--- a/src/browser/tests/intersection_observer/basic.html
+++ b/src/browser/tests/intersection_observer/basic.html
@@ -14,7 +14,7 @@
 
     observer.observe(target);
 
-    testing.eventually(() => {
+    testing.onload(() => {
         testing.expectEqual(true, callbackCalled);
         testing.expectEqual(1, entries.length);
 
@@ -41,7 +41,7 @@
       count += 1;
     }).observe(div);
 
-    testing.eventually(() => {
+    testing.onload(() => {
       testing.expectEqual(0, count);
     });
   }
@@ -56,7 +56,7 @@
     }).observe(div1);
 
     div2.appendChild(div1);
-    testing.eventually(() => {
+    testing.onload(() => {
       testing.expectEqual(1, count);
     });
   }
diff --git a/src/browser/tests/intersection_observer/disconnect.html b/src/browser/tests/intersection_observer/disconnect.html
index 6677f906..a00d2e8a 100644
--- a/src/browser/tests/intersection_observer/disconnect.html
+++ b/src/browser/tests/intersection_observer/disconnect.html
@@ -12,7 +12,7 @@
 
     observer.observe(target);
 
-    testing.eventually(() => {
+    testing.onload(() => {
         testing.expectEqual(1, callCount);
 
         observer.disconnect();
@@ -22,7 +22,7 @@
         const observer2 = new IntersectionObserver(() => {});
         observer2.observe(target);
 
-        testing.eventually(() => {
+        testing.onload(() => {
             observer2.disconnect();
             testing.expectEqual(1, callCount);
         });
diff --git a/src/browser/tests/intersection_observer/multiple_targets.html b/src/browser/tests/intersection_observer/multiple_targets.html
index 358a8355..a4d1c4d6 100644
--- a/src/browser/tests/intersection_observer/multiple_targets.html
+++ b/src/browser/tests/intersection_observer/multiple_targets.html
@@ -19,7 +19,7 @@
     observer.observe(target1);
     observer.observe(target2);
 
-    testing.eventually(() => {
+    testing.onload(() => {
         testing.expectEqual(2, entryCount);
         testing.expectTrue(seenTargets.has(target1));
         testing.expectTrue(seenTargets.has(target2));
diff --git a/src/browser/tests/intersection_observer/unobserve.html b/src/browser/tests/intersection_observer/unobserve.html
index 8d37e2c3..3f309362 100644
--- a/src/browser/tests/intersection_observer/unobserve.html
+++ b/src/browser/tests/intersection_observer/unobserve.html
@@ -20,7 +20,7 @@
     observer.unobserve(target1);
     observer.observe(target2);
 
-    testing.eventually(() => {
+    testing.onload(() => {
         // Should only see target2, not target1
         testing.expectEqual(1, seenTargets.length);
         testing.expectEqual(target2, seenTargets[0]);
diff --git a/src/browser/tests/legacy/cssom/css_stylesheet.html b/src/browser/tests/legacy/cssom/css_stylesheet.html
index ed2e876b..20ee1dfe 100644
--- a/src/browser/tests/legacy/cssom/css_stylesheet.html
+++ b/src/browser/tests/legacy/cssom/css_stylesheet.html
@@ -12,5 +12,5 @@
 
   let replaced = false;
   css.replace('body{}').then(() => replaced = true);
-  testing.eventually(() => testing.expectEqual(true, replaced));
+  testing.onload(() => testing.expectEqual(true, replaced));
 </script>
diff --git a/src/browser/tests/legacy/dom/animation.html b/src/browser/tests/legacy/dom/animation.html
index 27e562a0..e109ab0e 100644
--- a/src/browser/tests/legacy/dom/animation.html
+++ b/src/browser/tests/legacy/dom/animation.html
@@ -11,5 +11,5 @@
     cb.push('finished');
     cb.push(x == a1);
   });
-  testing.eventually(() => testing.expectEqual(['finished', true], cb));
+  testing.onload(() => testing.expectEqual(['finished', true], cb));
 </script>
diff --git a/src/browser/tests/legacy/dom/intersection_observer.html b/src/browser/tests/legacy/dom/intersection_observer.html
index c48f4754..d569894f 100644
--- a/src/browser/tests/legacy/dom/intersection_observer.html
+++ b/src/browser/tests/legacy/dom/intersection_observer.html
@@ -11,7 +11,7 @@
       count += 1;
     }).observe(div);
 
-    testing.eventually(() => {
+    testing.onload(() => {
       testing.expectEqual(0, count);
     });
   }
@@ -27,7 +27,7 @@
     }).observe(div1);
 
     div2.appendChild(div1);
-    testing.eventually(() => {
+    testing.onload(() => {
       testing.expectEqual(1, count);
     });
   }
@@ -51,7 +51,7 @@
     observer.observe(div1);
     testing.expectEqual(0, count);
 
-    testing.eventually(() => {
+    testing.onload(() => {
       testing.expectEqual(1, count);
     });
   }
@@ -75,7 +75,7 @@
     testing.expectEqual(0, count);
 
     observer.unobserve(div1);
-    testing.eventually(() => {
+    testing.onload(() => {
       testing.expectEqual(0, count);
     });
   }
@@ -100,7 +100,7 @@
     testing.expectEqual(0, count);
     observer.disconnect();
 
-    testing.eventually(() => {
+    testing.onload(() => {
       testing.expectEqual(0, count);
     });
   }
@@ -117,7 +117,7 @@
     document.body.appendChild(div1);
     new IntersectionObserver(entries => { entry = entries[0]; }).observe(div1);
 
-    testing.eventually(() => {
+    testing.onload(() => {
       testing.expectEqual(125, entry.boundingClientRect.x);
       testing.expectEqual(1, entry.intersectionRatio);
       testing.expectEqual(125, entry.intersectionRect.x);
@@ -150,7 +150,7 @@
     observer.observe(div);
     capture.push('post-observe');
 
-    testing.eventually(() => {
+    testing.onload(() => {
       testing.expectEqual([
         'pre-append',
         'post-append',
diff --git a/src/browser/tests/legacy/html/abort_controller.html b/src/browser/tests/legacy/html/abort_controller.html
index fc5a1cdf..5f9f0ee0 100644
--- a/src/browser/tests/legacy/html/abort_controller.html
+++ b/src/browser/tests/legacy/html/abort_controller.html
@@ -31,7 +31,7 @@
 
 <script id=timeout>
   var s3 = AbortSignal.timeout(10);
-  testing.eventually(() => {
+  testing.onload(() => {
     testing.expectEqual(true, s3.aborted);
     testing.expectEqual('TimeoutError', s3.reason);
     testing.expectError('Error: TimeoutError', () => {
diff --git a/src/browser/tests/legacy/html/history/history.html b/src/browser/tests/legacy/html/history/history.html
index 824e0e02..3f6d0708 100644
--- a/src/browser/tests/legacy/html/history/history.html
+++ b/src/browser/tests/legacy/html/history/history.html
@@ -28,7 +28,7 @@
         popstateEventState = event.state;
     });
 
-    testing.eventually(() => {
+    testing.onload(() => {
       testing.expectEqual(true, popstateEventFired);
       testing.expectEqual(state, popstateEventState);
     })
diff --git a/src/browser/tests/legacy/html/history/history2.html b/src/browser/tests/legacy/html/history/history2.html
index cb251092..89fc73b4 100644
--- a/src/browser/tests/legacy/html/history/history2.html
+++ b/src/browser/tests/legacy/html/history/history2.html
@@ -14,7 +14,7 @@
         popstateEventState = event.state;
     };
 
-    testing.eventually(() => {
+    testing.onload(() => {
       testing.expectEqual(true, popstateEventFired);
       testing.expectEqual(state, popstateEventState);
     })
diff --git a/src/browser/tests/legacy/html/script/inline_defer.html b/src/browser/tests/legacy/html/script/inline_defer.html
index ec5b44c6..11350032 100644
--- a/src/browser/tests/legacy/html/script/inline_defer.html
+++ b/src/browser/tests/legacy/html/script/inline_defer.html
@@ -24,5 +24,5 @@
   // inline script should ignore defer and async attributes. If we don't do
   // this correctly, we'd end up in an infinite loop
   // https://github.com/lightpanda-io/browser/issues/1014
-  testing.eventually(() => testing.expectEqual(2, dyn1_loaded));
+  testing.onload(() => testing.expectEqual(2, dyn1_loaded));
 </script>
diff --git a/src/browser/tests/legacy/html/slot.html b/src/browser/tests/legacy/html/slot.html
index 026e13e0..36e3bc1f 100644
--- a/src/browser/tests/legacy/html/slot.html
+++ b/src/browser/tests/legacy/html/slot.html
@@ -94,7 +94,7 @@
     lp.appendChild(div);
     testing.expectEqual(slot, div.assignedSlot);
 
-    testing.eventually(() => {
+    testing.onload(() => {
       testing.expectEqual(1, calls)
     });
   }
@@ -113,7 +113,7 @@
 
     const div = $('#s2');
     div.removeAttribute('slot');
-    testing.eventually(() => {
+    testing.onload(() => {
       testing.expectEqual(1, calls)
     });
   }
@@ -132,7 +132,7 @@
 
     const div = $('#s3');
     div.slot = 'other';
-    testing.eventually(() => {
+    testing.onload(() => {
       testing.expectEqual(1, calls)
     });
   }
@@ -154,7 +154,7 @@
     div.slot = 'other';
     lp.appendChild(div);
     div.slot = 'slot-1'
-    testing.eventually(() => {
+    testing.onload(() => {
       testing.expectEqual(1, calls)
     });
   }
@@ -172,7 +172,7 @@
     });
 
     $('#s5').remove();
-    testing.eventually(() => {
+    testing.onload(() => {
       testing.expectEqual(1, calls)
     });
   }
diff --git a/src/browser/tests/legacy/window/window.html b/src/browser/tests/legacy/window/window.html
index 7a2a7374..dee57062 100644
--- a/src/browser/tests/legacy/window/window.html
+++ b/src/browser/tests/legacy/window/window.html
@@ -16,7 +16,7 @@
     start = timestamp;
   }
   requestAnimationFrame(step);
-  testing.eventually(() => {
+  testing.onload(() => {
     testing.expectEqual(true, start > 0)
   });
 
@@ -24,23 +24,23 @@
     start = 0;
   });
   cancelAnimationFrame(request_id);
-  testing.eventually(() => testing.expectEqual(true, start > 0));
+  testing.onload(() => testing.expectEqual(true, start > 0));
 </script>
 
 <script id=setTimeout>
   let longCall = false;
   window.setTimeout(() => {longCall = true}, 5001);
-  testing.eventually(() => testing.expectEqual(false, longCall));
+  testing.onload(() => testing.expectEqual(false, longCall));
 
   let wst1 = 0;
   window.setTimeout(() => {wst1 += 1}, 1);
-  testing.eventually(() => testing.expectEqual(1, wst1));
+  testing.onload(() => testing.expectEqual(1, wst1));
 
   let wst2 = 1;
   window.setTimeout((a, b) => {
     wst2 = a + b;
   }, 1, 2, 3);
-  testing.eventually(() => testing.expectEqual(5, wst2));
+  testing.onload(() => testing.expectEqual(5, wst2));
 </script>
 
 <script id=eventTarget>
@@ -70,7 +70,7 @@
 <script id=queueMicroTask>
   var qm = false;
   window.queueMicrotask(() => {qm = true });
-  testing.eventually(() => testing.expectEqual(true, qm));
+  testing.onload(() => testing.expectEqual(true, qm));
 </script>
 
 <script id=DOMContentLoaded>
@@ -79,7 +79,7 @@
   window.addEventListener('DOMContentLoaded', (e) => {
     dcl = e.target == document;
   });
-  testing.eventually(() => testing.expectEqual(true, dcl));
+  testing.onload(() => testing.expectEqual(true, dcl));
 </script>
 
 <script id=window.onload>
@@ -97,7 +97,7 @@
   window.onload = callback;
   testing.expectEqual(callback, window.onload);
 
-  testing.eventually(() => testing.expectEqual(true, isDocumentTarget));
+  testing.onload(() => testing.expectEqual(true, isDocumentTarget));
 </script>
 
 <script id=reportError>
diff --git a/src/browser/tests/page/blob.html b/src/browser/tests/page/blob.html
index 434c1ce6..d688eec0 100644
--- a/src/browser/tests/page/blob.html
+++ b/src/browser/tests/page/blob.html
@@ -12,7 +12,7 @@
     document.body.appendChild(iframe);
     iframe.src = blob_url;
 
-    testing.eventually(() => {
+    testing.onload(() => {
       testing.expectEqual('Hello Blob', iframe.contentDocument.getElementById('test').textContent);
     });
   }
@@ -33,7 +33,7 @@
     document.body.appendChild(iframe2);
     iframe2.src = url2;
 
-    testing.eventually(() => {
+    testing.onload(() => {
       testing.expectEqual('First', iframe1.contentDocument.body.textContent);
       testing.expectEqual('Second', iframe2.contentDocument.body.textContent);
     });
diff --git a/src/browser/tests/page/load_event.html b/src/browser/tests/page/load_event.html
index 1776313c..abb4ae11 100644
--- a/src/browser/tests/page/load_event.html
+++ b/src/browser/tests/page/load_event.html
@@ -9,7 +9,7 @@
     call1 = true;
   });
 
-  testing.eventually(() => {
+  testing.onload(() => {
     testing.expectEqual(document, ex1.target);
     testing.expectEqual('DOMContentLoaded', ex1.type);
     testing.expectEqual(true, call1);
diff --git a/src/browser/tests/performance_observer/performance_observer.html b/src/browser/tests/performance_observer/performance_observer.html
index 3289ab41..40ed883d 100644
--- a/src/browser/tests/performance_observer/performance_observer.html
+++ b/src/browser/tests/performance_observer/performance_observer.html
@@ -86,7 +86,7 @@
   // With buffered: true, existing marks should be delivered
   observer.observe({ type: "mark", buffered: true });
 
-  testing.eventually(() => {
+  testing.onload(() => {
     testing.expectEqual(true, receivedEntries !== null);
     testing.expectEqual(2, receivedEntries.length);
     testing.expectEqual("early1", receivedEntries[0].name);
diff --git a/src/browser/tests/selection.html b/src/browser/tests/selection.html
index a1e73bff..c3c8a887 100644
--- a/src/browser/tests/selection.html
+++ b/src/browser/tests/selection.html
@@ -582,7 +582,7 @@
     document.removeEventListener('selectionchange', listener);
     textNode.textContent = "The quick brown fox";
 
-    testing.eventually(() => {
+    testing.onload(() => {
       testing.expectEqual(14, eventCount);
       testing.expectEqual('selectionchange', lastEvent.type);
       testing.expectEqual(document, lastEvent.target);
diff --git a/src/browser/tests/testing.js b/src/browser/tests/testing.js
index 2e33c1d3..3a8eeed3 100644
--- a/src/browser/tests/testing.js
+++ b/src/browser/tests/testing.js
@@ -52,10 +52,10 @@
     throw new Error('no error');
   }
 
-  function eventually(cb) {
+  function onload(cb) {
     const script_id = _currentScriptId();
     if (!script_id) {
-      throw new Error('testing.eventually called outside of a script');
+      throw new Error('testing.onload called outside of a script');
     }
     eventuallies.push({
       callback: cb,
@@ -110,7 +110,7 @@
     expectEqual: expectEqual,
     expectError: expectError,
     withError: withError,
-    eventually: eventually,
+    onload: onload,
     IS_TEST_RUNNER: IS_TEST_RUNNER,
     HOST: '127.0.0.1',
     ORIGIN: 'http://127.0.0.1:9582',
diff --git a/src/browser/tests/window/body_onload1.html b/src/browser/tests/window/body_onload1.html
index 3858810e..ba2a437c 100644
--- a/src/browser/tests/window/body_onload1.html
+++ b/src/browser/tests/window/body_onload1.html
@@ -10,7 +10,7 @@
     testing.expectEqual(window, e.currentTarget);
   }
 
-  testing.eventually(() => {
+  testing.onload(() => {
     testing.expectEqual(1, called);
   });
 </script>
diff --git a/src/browser/tests/window/body_onload2.html b/src/browser/tests/window/body_onload2.html
index 0403b30c..eeff067e 100644
--- a/src/browser/tests/window/body_onload2.html
+++ b/src/browser/tests/window/body_onload2.html
@@ -7,7 +7,7 @@
   // Verify: handler fires, "event" parameter is a proper Event, and handler is a function.
   let loadEvent = null;
 
-  testing.eventually(() => {
+  testing.onload(() => {
     testing.expectEqual("function", typeof document.body.onload);
     testing.expectTrue(loadEvent instanceof Event);
     testing.expectEqual("load", loadEvent.type);
diff --git a/src/browser/tests/window/body_onload3.html b/src/browser/tests/window/body_onload3.html
index 875be388..fdc5987a 100644
--- a/src/browser/tests/window/body_onload3.html
+++ b/src/browser/tests/window/body_onload3.html
@@ -7,7 +7,7 @@
   // Verify: handler fires exactly once, and body.onload reflects to window.onload.
   let called = 0;
 
-  testing.eventually(() => {
+  testing.onload(() => {
     // The attribute handler should have fired exactly once.
     testing.expectEqual(1, called);
 
diff --git a/src/browser/tests/window/timers.html b/src/browser/tests/window/timers.html
index 0e8a09e1..9e22d4d2 100644
--- a/src/browser/tests/window/timers.html
+++ b/src/browser/tests/window/timers.html
@@ -17,7 +17,7 @@
   testing.expectEqual(true, timer1 != timer2);
 
 
-  testing.eventually(() => {
+  testing.onload(() => {
     testing.expectEqual(true, set_interval1);
     testing.expectEqual(false, set_interval2);
   });
@@ -29,7 +29,7 @@
   window.setTimeout((a, b) => {
     wst2 = a + b;
   }, 1, 2, 3);
-  testing.eventually(() => testing.expectEqual(5, wst2));
+  testing.onload(() => testing.expectEqual(5, wst2));
 </script>
 
 <script id=invalid-timer-clear>
diff --git a/src/browser/tests/window/window.html b/src/browser/tests/window/window.html
index e4094f9b..13cd40e8 100644
--- a/src/browser/tests/window/window.html
+++ b/src/browser/tests/window/window.html
@@ -43,7 +43,7 @@
 
   // noop
   window.removeEventListener('load', fn);
-  testing.eventually(() => {
+  testing.onload(() => {
     testing.expectEqual(1, call1);
     testing.expectEqual(2, call2);
   });
@@ -285,6 +285,6 @@
       unhandledCalled += 1;
     });
     Promise.reject({x: 'Fail'});
-    testing.eventually(() => testing.expectEqual(2, unhandledCalled));
+    testing.onload(() => testing.expectEqual(2, unhandledCalled));
   }
 </script>