diff --git a/skyvern-frontend/src/components/DataSchemaInputGroup/WorkflowDataSchemaInputGroup.tsx b/skyvern-frontend/src/components/DataSchemaInputGroup/WorkflowDataSchemaInputGroup.tsx
index 22eaee1f..a2ac5ba4 100644
--- a/skyvern-frontend/src/components/DataSchemaInputGroup/WorkflowDataSchemaInputGroup.tsx
+++ b/skyvern-frontend/src/components/DataSchemaInputGroup/WorkflowDataSchemaInputGroup.tsx
@@ -12,11 +12,12 @@ import { useCredentialGetter } from "@/hooks/useCredentialGetter";
 import { getClient } from "@/api/AxiosClient";
 import { CodeEditor } from "@/routes/workflows/components/CodeEditor";
 import { helpTooltips } from "@/routes/workflows/editor/helpContent";
-import { useState } from "react";
+import { useMemo, useState } from "react";
 import { AutoResizingTextarea } from "../AutoResizingTextarea/AutoResizingTextarea";
 import { Button } from "../ui/button";
 import { AxiosError } from "axios";
 import { toast } from "../ui/use-toast";
+import { cn } from "@/util/utils";
 
 type Props = {
   value: string;
@@ -35,6 +36,42 @@ function WorkflowDataSchemaInputGroup({
   const [generateWithAIActive, setGenerateWithAIActive] = useState(false);
   const [generateWithAIPrompt, setGenerateWithAIPrompt] = useState("");
 
+  function computeJsonError(
+    jsonText: string,
+  ): { message: string; line?: number; column?: number } | null {
+    try {
+      JSON.parse(jsonText);
+      return null;
+    } catch (e) {
+      const message = e instanceof Error ? e.message : "Invalid JSON";
+      // Try to extract position and compute line/column for friendlier feedback
+      const match = message.match(/position\s+(\d+)/i);
+      if (!match) {
+        return { message };
+      }
+      const pos = Number(match[1]);
+      if (Number.isNaN(pos)) {
+        return { message };
+      }
+      let line = 1;
+      let col = 1;
+      for (let i = 0; i < Math.min(pos, jsonText.length); i++) {
+        if (jsonText[i] === "\n") {
+          line += 1;
+          col = 1;
+        } else {
+          col += 1;
+        }
+      }
+      return { message, line, column: col };
+    }
+  }
+
+  const jsonError = useMemo(() => {
+    if (value === "null") return null;
+    return computeJsonError(value);
+  }, [value]);
+
   const getDataSchemaSuggestionMutation = useMutation({
     mutationFn: async () => {
       const client = await getClient(credentialGetter);
@@ -121,13 +158,27 @@ function WorkflowDataSchemaInputGroup({
               )}
             </div>
           ) : null}
-          <CodeEditor
-            language="json"
-            value={value}
-            onChange={onChange}
-            className="nopan"
-            fontSize={8}
-          />
+          <div
+            className={cn(
+              "rounded-md",
+              jsonError ? "ring-1 ring-red-500" : undefined,
+            )}
+          >
+            <CodeEditor
+              language="json"
+              value={value}
+              onChange={onChange}
+              className="nopan"
+              fontSize={8}
+            />
+          </div>
+          {jsonError && (
+            <div className="text-xs text-red-400">
+              {jsonError.line && jsonError.column
+                ? `Invalid JSON (${jsonError.line}:${jsonError.column}) — ${jsonError.message}`
+                : `Invalid JSON — ${jsonError.message}`}
+            </div>
+          )}
         </div>
       )}
     </div>
diff --git a/skyvern-frontend/src/routes/workflows/editor/FlowRenderer.tsx b/skyvern-frontend/src/routes/workflows/editor/FlowRenderer.tsx
index 5bfb3a12..22700d87 100644
--- a/skyvern-frontend/src/routes/workflows/editor/FlowRenderer.tsx
+++ b/skyvern-frontend/src/routes/workflows/editor/FlowRenderer.tsx
@@ -79,6 +79,8 @@ import {
   getWorkflowSettings,
   layout,
 } from "./workflowEditorUtils";
+import { getWorkflowErrors } from "./workflowEditorUtils";
+import { toast } from "@/components/ui/use-toast";
 import { useAutoPan } from "./useAutoPan";
 
 const nextTick = () => new Promise((resolve) => setTimeout(resolve, 0));
@@ -373,8 +375,25 @@ function FlowRenderer({
     setGetSaveDataRef.current(constructSaveData);
   }, [constructSaveData]);
 
-  async function handleSave() {
-    return await saveWorkflow.mutateAsync();
+  async function handleSave(): Promise<boolean> {
+    // Validate before saving; block if any workflow errors exist
+    const errors = getWorkflowErrors(nodes);
+    if (errors.length > 0) {
+      toast({
+        title: "Can not save workflow because of errors:",
+        description: (
+          <div className="space-y-2">
+            {errors.map((error) => (
+              <p key={error}>{error}</p>
+            ))}
+          </div>
+        ),
+        variant: "destructive",
+      });
+      return false;
+    }
+    await saveWorkflow.mutateAsync();
+    return true;
   }
 
   function deleteNode(id: string) {
@@ -605,8 +624,10 @@ function FlowRenderer({
             </Button>
             <Button
               onClick={() => {
-                handleSave().then(() => {
-                  blocker.proceed?.();
+                handleSave().then((ok) => {
+                  if (ok) {
+                    blocker.proceed?.();
+                  }
                 });
               }}
               disabled={workflowChangesStore.saveIsPending}
diff --git a/skyvern-frontend/src/routes/workflows/editor/workflowEditorUtils.ts b/skyvern-frontend/src/routes/workflows/editor/workflowEditorUtils.ts
index 23a52aea..0f320c0b 100644
--- a/skyvern-frontend/src/routes/workflows/editor/workflowEditorUtils.ts
+++ b/skyvern-frontend/src/routes/workflows/editor/workflowEditorUtils.ts
@@ -2186,6 +2186,14 @@ function getWorkflowErrors(nodes: Array<AppNode>): Array<string> {
     } catch {
       errors.push(`${node.data.label}: Error messages is not valid JSON.`);
     }
+    // Validate Task data schema JSON when enabled (value different from "null")
+    if (node.data.dataSchema && node.data.dataSchema !== "null") {
+      try {
+        JSON.parse(node.data.dataSchema);
+      } catch {
+        errors.push(`${node.data.label}: Data schema is not valid JSON.`);
+      }
+    }
   });
 
   const validationNodes = nodes.filter(isValidationNode);
@@ -2217,6 +2225,14 @@ function getWorkflowErrors(nodes: Array<AppNode>): Array<string> {
     if (node.data.dataExtractionGoal.length === 0) {
       errors.push(`${node.data.label}: Data extraction goal is required.`);
     }
+    // Validate Extraction data schema JSON when enabled (value different from "null")
+    if (node.data.dataSchema && node.data.dataSchema !== "null") {
+      try {
+        JSON.parse(node.data.dataSchema);
+      } catch {
+        errors.push(`${node.data.label}: Data schema is not valid JSON.`);
+      }
+    }
   });
 
   const textPromptNodes = nodes.filter(isTextPromptNode);