diff --git a/src/lib/util/redirect.test.ts b/src/lib/util/redirect.test.ts
new file mode 100644
index 00000000..fd465593
--- /dev/null
+++ b/src/lib/util/redirect.test.ts
@@ -0,0 +1,51 @@
+import { describe, expect, it } from 'vitest';
+import { buildRedirectUrl } from './redirect';
+
+const mockLocation = (url: string): Location => {
+  const parsed = new URL(url);
+  return { hash: parsed.hash, search: parsed.search } as Location;
+};
+
+describe('buildRedirectUrl', () => {
+  it('should redirect to /edit by default when hash is empty', () => {
+    expect(buildRedirectUrl(mockLocation('https://mermaid.live/'))).toBe('/edit');
+  });
+
+  it('should preserve search params', () => {
+    expect(buildRedirectUrl(mockLocation('https://mermaid.live/?utm_source=github'))).toBe(
+      '/edit?utm_source=github'
+    );
+  });
+
+  it('should extract route and fragment from old hash format', () => {
+    expect(buildRedirectUrl(mockLocation('https://mermaid.live/#/edit/pako:abc123'))).toBe(
+      '/edit#pako:abc123'
+    );
+  });
+
+  it('should place search params before the hash fragment', () => {
+    expect(
+      buildRedirectUrl(mockLocation('https://mermaid.live/?utm_source=twitter#/edit/pako:abc123'))
+    ).toBe('/edit?utm_source=twitter#pako:abc123');
+  });
+
+  it('should handle hash with view route', () => {
+    expect(buildRedirectUrl(mockLocation('https://mermaid.live/#/view/pako:xyz'))).toBe(
+      '/view#pako:xyz'
+    );
+  });
+
+  it('should default to edit when hash has no route', () => {
+    expect(buildRedirectUrl(mockLocation('https://mermaid.live/#somethingelse'))).toBe('/edit');
+  });
+
+  it('should handle multiple search params with hash', () => {
+    expect(
+      buildRedirectUrl(
+        mockLocation(
+          'https://mermaid.live/?utm_source=gh&utm_medium=link&utm_campaign=test#/edit/pako:data'
+        )
+      )
+    ).toBe('/edit?utm_source=gh&utm_medium=link&utm_campaign=test#pako:data');
+  });
+});
diff --git a/src/lib/util/redirect.ts b/src/lib/util/redirect.ts
new file mode 100644
index 00000000..26a1d923
--- /dev/null
+++ b/src/lib/util/redirect.ts
@@ -0,0 +1,15 @@
+/**
+ * Build the redirect URL for legacy root-path links.
+ * Extracts the route and fragment from the old hash-based URL format,
+ * and ensures search params (e.g. UTM) come before the hash fragment.
+ */
+export const buildRedirectUrl = (location: Location): string => {
+  const parts = location.hash.split('/');
+  let path = 'edit';
+  let fragment = '';
+  if (parts.length > 2) {
+    path = parts[1];
+    fragment = `#${parts[2]}`;
+  }
+  return `/${path}${location.search}${fragment}`;
+};
diff --git a/src/lib/util/stats.test.ts b/src/lib/util/stats.test.ts
new file mode 100644
index 00000000..da868d3e
--- /dev/null
+++ b/src/lib/util/stats.test.ts
@@ -0,0 +1,47 @@
+import { beforeEach, describe, expect, it } from 'vitest';
+import { getAnalyticsSafeUrl } from './stats';
+
+describe('getAnalyticsUrl', () => {
+  beforeEach(() => {
+    // Reset location to a clean state before each test
+    window.history.replaceState(null, '', '/');
+  });
+
+  it('should return origin and pathname for a simple URL', () => {
+    window.history.replaceState(null, '', '/edit');
+    const url = getAnalyticsSafeUrl();
+    expect(url).toBe(`${window.location.origin}/edit`);
+  });
+
+  it('should include search/query params (UTM parameters)', () => {
+    window.history.replaceState(null, '', '/edit?utm_source=github&utm_medium=docs');
+    const url = getAnalyticsSafeUrl();
+    expect(url).toBe(`${window.location.origin}/edit?utm_source=github&utm_medium=docs`);
+  });
+
+  it('should never include the hash', () => {
+    window.history.replaceState(null, '', '/edit#pako:someDiagramData');
+    // replaceState doesn't set hash, so set it via location
+    window.location.hash = '#pako:someDiagramData';
+    const url = getAnalyticsSafeUrl();
+    expect(url).not.toContain('#');
+    expect(url).not.toContain('pako:');
+    expect(url).toBe(`${window.location.origin}/edit`);
+  });
+
+  it('should include search params but exclude hash when both are present', () => {
+    window.history.replaceState(null, '', '/edit?utm_campaign=launch');
+    window.location.hash = '#pako:diagramDataHere';
+    const url = getAnalyticsSafeUrl();
+    expect(url).not.toContain('#');
+    expect(url).not.toContain('pako:');
+    expect(url).toContain('utm_campaign=launch');
+    expect(url).toBe(`${window.location.origin}/edit?utm_campaign=launch`);
+  });
+
+  it('should return just origin for root path with no params', () => {
+    window.history.replaceState(null, '', '/');
+    const url = getAnalyticsSafeUrl();
+    expect(url).toBe(`${window.location.origin}/`);
+  });
+});
diff --git a/src/lib/util/stats.ts b/src/lib/util/stats.ts
index 7bc0eaea..1aab01e6 100644
--- a/src/lib/util/stats.ts
+++ b/src/lib/util/stats.ts
@@ -23,6 +23,15 @@ export const initAnalytics = async (): Promise<void> => {
   }
 };
 
+/**
+ * Build the current page URL for analytics tracking.
+ * Includes origin, pathname, and search (for UTM params),
+ * but never the hash (which contains diagram data).
+ */
+export const getAnalyticsSafeUrl = (): string => {
+  return window.location.origin + window.location.pathname + window.location.search;
+};
+
 export const countLines = (code: string): number => {
   return (code.match(/\n/g)?.length ?? 0) + 1;
 };
@@ -111,11 +120,7 @@ export const logEvent = (
   if (timeouts.has(key)) {
     clearTimeout(timeouts.get(key));
   } else {
-    plausible.trackEvent(
-      name,
-      { props: data },
-      { url: window.location.origin + window.location.pathname }
-    );
+    plausible.trackEvent(name, { props: data }, { url: getAnalyticsSafeUrl() });
   }
   timeouts.set(
     key,
diff --git a/src/lib/util/util.ts b/src/lib/util/util.ts
index c252f370..2b272be1 100644
--- a/src/lib/util/util.ts
+++ b/src/lib/util/util.ts
@@ -5,7 +5,7 @@ import { initLoading } from './loading';
 import { isOnMermaidAI } from './migration/domainMigration';
 import { applyMigrations } from './migrations';
 import { initURLSubscription, loadState, updateCodeStore, verifyState } from './state';
-import { initAnalytics, plausible } from './stats';
+import { getAnalyticsSafeUrl, initAnalytics, plausible } from './stats';
 
 export const getDomain = (url?: string): string => {
   if (!url) return '';
@@ -30,7 +30,9 @@ export const initHandler = async (): Promise<void> => {
   syncDiagram();
   initURLSubscription();
   await initAnalytics();
-  plausible?.trackPageview({ url: window.location.origin + window.location.pathname });
+  plausible?.trackPageview({
+    url: getAnalyticsSafeUrl()
+  });
   verifyState();
 };
 
diff --git a/src/routes/+page.svelte b/src/routes/+page.svelte
index 4a12a8b8..ea21f3ca 100644
--- a/src/routes/+page.svelte
+++ b/src/routes/+page.svelte
@@ -1,16 +1,10 @@
 <script lang="ts">
   import { goto } from '$app/navigation';
+  import { buildRedirectUrl } from '$lib/util/redirect';
   import { onMount } from 'svelte';
-  import { base } from '$app/paths';
 
   onMount(async () => {
-    // Handle old live editor links and redirect to new version
-    const hash = window.location.hash.split('/');
-    let newURL = 'edit';
-    if (hash.length > 2) {
-      newURL = `${hash[1]}#${hash[2]}`;
-    }
-    await goto(`${base}/${newURL}`, {
+    await goto(buildRedirectUrl(window.location), {
       replaceState: true
     });
   });