diff --git a/app/jsonDoc.server.ts b/app/jsonDoc.server.ts
index a3b82f9d9..378c7d02a 100644
--- a/app/jsonDoc.server.ts
+++ b/app/jsonDoc.server.ts
@@ -45,6 +45,15 @@ export async function createFromUrlOrRawJson(
   if (isXML(urlOrJson)) {
     return createFromRawXml("Untitled", urlOrJson);
   }
+
+  try {
+    JSON.parse(urlOrJson);
+  } catch (error) {
+    const errorMessage = error instanceof Error ? error.message : "Invalid JSON format";
+    throw new Error(`Invalid JSON syntax: ${errorMessage}`);
+  }
+
+  return undefined;
 }
 
 export async function createFromUrl(
@@ -158,7 +167,7 @@ function isJSON(possibleJson: string): boolean {
   try {
     JSON.parse(possibleJson);
     return true;
-  } catch (e: any) {
-    throw new Error(e.message);
+  } catch {
+    return false;
   }
 }
diff --git a/app/routes/actions/createFromUrl.ts b/app/routes/actions/createFromUrl.ts
index 9e02761b9..22ece58d0 100644
--- a/app/routes/actions/createFromUrl.ts
+++ b/app/routes/actions/createFromUrl.ts
@@ -58,7 +58,11 @@ export let action: ActionFunction = async ({ request, context }) => {
     return redirect(`/j/${doc.id}`);
   } catch (e) {
     if (e instanceof Error) {
-      setErrorMessage(toastCookie, e.message, "Something went wrong");
+      if (e.message.includes("Invalid JSON syntax")) {
+        setErrorMessage(toastCookie, "Invalid JSON", e.message);
+      } else {
+        setErrorMessage(toastCookie, e.message, "Something went wrong");
+      }
     } else {
       setErrorMessage(toastCookie, "Unknown error", "Something went wrong");
     }