diff --git a/.changeset/tough-bikes-study.md b/.changeset/tough-bikes-study.md
new file mode 100644
index 000000000..4ab023c24
--- /dev/null
+++ b/.changeset/tough-bikes-study.md
@@ -0,0 +1,6 @@
+---
+'@web/test-runner-selenium': patch
+'@web/test-runner-webdriver': patch
+---
+
+Navigations to blank pages now use `about:blank` instead of `data:,`.
diff --git a/packages/test-runner-selenium/src/IFrameManager.ts b/packages/test-runner-selenium/src/IFrameManager.ts
index d030aa8e6..98d67a4a4 100644
--- a/packages/test-runner-selenium/src/IFrameManager.ts
+++ b/packages/test-runner-selenium/src/IFrameManager.ts
@@ -139,7 +139,7 @@ export class IFrameManager {
       }
 
       // set src after retreiving values to avoid the iframe from navigating away
-      iframe.src = "data:,";
+      iframe.src = "about:blank";
       return { testCoverage: testCoverage };
     `);
 
diff --git a/packages/test-runner-webdriver/src/IFrameManager.ts b/packages/test-runner-webdriver/src/IFrameManager.ts
index e1fa9a037..cd4244701 100644
--- a/packages/test-runner-webdriver/src/IFrameManager.ts
+++ b/packages/test-runner-webdriver/src/IFrameManager.ts
@@ -134,7 +134,7 @@ export class IFrameManager {
       iframe.addEventListener('load', loaded);
       iframe.addEventListener('error', loaded);
       // set src after retrieving values to avoid the iframe from navigating away
-      iframe.src = "data:,";
+      iframe.src = "about:blank";
     `);
 
     if (!validateBrowserResult(returnValue)) {
diff --git a/packages/test-runner-webdriver/src/SessionManager.ts b/packages/test-runner-webdriver/src/SessionManager.ts
index 98ddc6f8e..e9cf18045 100644
--- a/packages/test-runner-webdriver/src/SessionManager.ts
+++ b/packages/test-runner-webdriver/src/SessionManager.ts
@@ -73,7 +73,7 @@ export class SessionManager {
     const { testCoverage } = returnValue;
 
     // navigate to an empty page to kill any running code on the page
-    await this.driver.navigateTo('data:,');
+    await this.driver.navigateTo('about:blank');
 
     this.urlMap.delete(id);