diff --git a/packages/next-sandbox/src/highlighted-json.tsx b/packages/next-sandbox/src/highlighted-json.tsx
new file mode 100644
index 0000000..cc2674f
--- /dev/null
+++ b/packages/next-sandbox/src/highlighted-json.tsx
@@ -0,0 +1,49 @@
+import React from 'react';
+
+function syntaxHighlightReact(jsonStr: string) {
+  if (!jsonStr) return null;
+
+  const regex =
+    /("(\\u[a-zA-Z0-9]{4}|\\[^u]|[^\\"])*"(\s*:)?|\b(true|false|null)\b|-?\d+(?:\.\d*)?(?:[eE][+\-]?\d+)?)/g;
+  let lastIndex = 0;
+  const tokens = [];
+  let match;
+  let key = 0;
+
+  while ((match = regex.exec(jsonStr)) !== null) {
+    if (match.index > lastIndex) {
+      tokens.push(jsonStr.slice(lastIndex, match.index));
+    }
+    const token = match[0];
+    let cls = 'number';
+    if (/^"/.test(token)) {
+      cls = /:$/.test(token) ? 'key' : 'string';
+    } else if (/true|false/.test(token)) {
+      cls = 'boolean';
+    } else if (/null/.test(token)) {
+      cls = 'null';
+    }
+    tokens.push(
+      <span key={key++} className={cls}>
+        {token}
+      </span>,
+    );
+    lastIndex = regex.lastIndex;
+  }
+
+  if (lastIndex < jsonStr.length) {
+    tokens.push(jsonStr.slice(lastIndex));
+  }
+
+  return tokens;
+}
+
+interface HighlightedJSONProps {
+  jsonStr: string;
+}
+
+export default function HighlightedJSON({ jsonStr }: HighlightedJSONProps) {
+  const tokens = syntaxHighlightReact(jsonStr);
+
+  return <pre className="log-content">{tokens}</pre>;
+}
diff --git a/packages/next-sandbox/src/log-drawer.tsx b/packages/next-sandbox/src/log-drawer.tsx
index 9a36876..032ae19 100644
--- a/packages/next-sandbox/src/log-drawer.tsx
+++ b/packages/next-sandbox/src/log-drawer.tsx
@@ -5,6 +5,7 @@ import React from 'react';
 import { useSandbox } from './sandbox-context';
 import LoaderIcon from './icons/loader-icon';
 import PlayIcon from './icons/play-icon';
+import HighlightedJSON from './highlighted-json';
 
 interface LogDrawerProps {
   open: boolean;
@@ -56,12 +57,13 @@ export default function LogDrawer({
                 ) : (
                   [...currentRecords].reverse().map((record, idx) => (
                     <div key={idx} className="log-item">
-                      <pre
-                        data-error-message={record.status === 'error'}
-                        className="log-content"
-                      >
-                        {record.output}
-                      </pre>
+                      {record.status === 'success' ? (
+                        <HighlightedJSON jsonStr={record.output} />
+                      ) : (
+                        <pre className="log-content log-error">
+                          {record.output}
+                        </pre>
+                      )}
                       <div className="log-meta">
                         <p className="log-time">
                           {new Date(record.timestamp).toLocaleTimeString() ??
diff --git a/packages/next-sandbox/src/style.css b/packages/next-sandbox/src/style.css
index 8ccad0a..d3563a4 100644
--- a/packages/next-sandbox/src/style.css
+++ b/packages/next-sandbox/src/style.css
@@ -271,7 +271,23 @@
   overflow-x: auto;
 }
 
-.log-content[data-error-message='true'] {
+.log-content .string {
+  color: var(--color-success);
+}
+.log-content .number {
+  color: darkorange;
+}
+.log-content .boolean {
+  color: var(--color-blue);
+}
+.log-content .null {
+  color: rgb(195, 120, 215);
+}
+.log-content .key {
+  color: var(--color-danger);
+}
+
+.log-error {
   color: var(--color-danger);
 }