diff --git a/app/src/components/contribute/ContributionFlow.tsx b/app/src/components/contribute/ContributionFlow.tsx
index df04860a..4250c0f3 100644
--- a/app/src/components/contribute/ContributionFlow.tsx
+++ b/app/src/components/contribute/ContributionFlow.tsx
@@ -1,6 +1,7 @@
 import { defineStepper } from "@stepperize/react";
 import { ChevronRight } from "lucide-react";
 import { Fragment, useEffect, useMemo, useRef, useState } from "react";
+import { useBlocker, useLocation } from "@tanstack/react-router";
 import { toast } from "sonner";
 
 import type { Dispatch, SetStateAction } from "react";
@@ -850,6 +851,44 @@ function Inner({
     }
   };
 
+  const [hasUnsavedChanges, setHasUnsavedChanges] = useState(false);
+
+  useBlocker({
+    shouldBlockFn: ({ current, next }) => {
+      const isLeaving =
+        current.routeId === "/contribute" && next.routeId !== "/contribute";
+
+      if (isLeaving) {
+        const shouldLeave = window.confirm(
+          "Are you sure you want to leave? You have unsaved changes."
+        );
+        return !shouldLeave;
+      }
+
+      return false;
+    },
+    enableBeforeUnload: hasUnsavedChanges,
+  });
+
+  // Remove draft from sessionStorage if user leaves /contribute page
+  const location = useLocation();
+  const pathname = location.pathname;
+
+  // Handle when user leaves page
+  useEffect(() => {
+    if (pathname === "/contribute") {
+      sessionStorage.setItem("wasOnContributePage", "true");
+    } else {
+      const wasOnContribute =
+        sessionStorage.getItem("wasOnContributePage") === "true";
+      if (wasOnContribute) {
+        setHasUnsavedChanges(true);
+        if (type) clearStoredDraft(type);
+        sessionStorage.removeItem("wasOnContributePage");
+      }
+    }
+  }, [pathname]);
+
   if (skipTypeStep && !type) return null;
 
   return (
diff --git a/app/src/lib/contributionStorage.ts b/app/src/lib/contributionStorage.ts
index 5e23daa2..83c5739c 100644
--- a/app/src/lib/contributionStorage.ts
+++ b/app/src/lib/contributionStorage.ts
@@ -39,7 +39,7 @@ const DRAFT_SCHEMAS: Record<ContributionType, z.ZodType> = {
 };
 
 /**
- * Safely reads a contribution draft from localStorage.
+ * Safely reads a contribution draft from sessionStorage.
  * Handles SSR (returns null when window is not defined) and JSON parse errors.
  * A draft that doesn't match the expected shape is dropped and cleared, since
  * loading one into form state crashes the first render that touches it.
@@ -51,7 +51,7 @@ export function getStoredDraft<T>(
 
   let parsed: unknown;
   try {
-    const raw = window.localStorage.getItem(STORAGE_KEYS[type]);
+    const raw = window.sessionStorage.getItem(STORAGE_KEYS[type]);
     if (!raw) return null;
     parsed = JSON.parse(raw);
   } catch (error) {
@@ -74,7 +74,7 @@ export function getStoredDraft<T>(
 }
 
 /**
- * Safely writes a contribution draft to localStorage.
+ * Safely writes a contribution draft to sessionStorage.
  */
 export function setStoredDraft<T>(
   type: ContributionType,
@@ -83,20 +83,20 @@ export function setStoredDraft<T>(
   if (typeof window === "undefined") return;
 
   try {
-    window.localStorage.setItem(STORAGE_KEYS[type], JSON.stringify(draft));
+    window.sessionStorage.setItem(STORAGE_KEYS[type], JSON.stringify(draft));
   } catch (error) {
-    console.warn(`Failed to save draft to localStorage for ${type}:`, error);
+    console.warn(`Failed to save draft to sessionStorage for ${type}:`, error);
   }
 }
 
 /**
- * Clears the stored draft for a given contribution type from localStorage.
+ * Clears the stored draft for a given contribution type from sessionStorage.
  */
 export function clearStoredDraft(type: ContributionType): void {
   if (typeof window === "undefined") return;
 
   try {
-    window.localStorage.removeItem(STORAGE_KEYS[type]);
+    window.sessionStorage.removeItem(STORAGE_KEYS[type]);
   } catch (error) {
     console.warn(`Failed to clear stored draft for ${type}:`, error);
   }
@@ -109,14 +109,14 @@ export function hasStoredDraft(type: ContributionType): boolean {
   if (typeof window === "undefined") return false;
 
   try {
-    return window.localStorage.getItem(STORAGE_KEYS[type]) !== null;
+    return window.sessionStorage.getItem(STORAGE_KEYS[type]) !== null;
   } catch {
     return false;
   }
 }
 
 /**
- * Clears all stored drafts for all contribution types from localStorage.
+ * Clears all stored drafts for all contribution types from sessionStorage.
  */
 export function clearAllStoredDrafts(): void {
   const types = Object.keys(STORAGE_KEYS) as Array<ContributionType>;
@@ -130,7 +130,7 @@ export interface ContributionSaveControls {
 }
 
 /**
- * Hook to automatically and debouncingly save contribution form data to localStorage.
+ * Hook to automatically and debouncingly save contribution form data to sessionStorage.
  * Passing a null type disables saving, flushing anything already queued.
  * Flushes pending changes immediately on component unmount.
  */