diff --git a/CHANGELOG.md b/CHANGELOG.md
index 36806311..f03f19df 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -9,6 +9,7 @@ All notable changes to this project will be documented in this file.
 ### Changed
 - Migrated AI logic from numbered demo folders into `src/`; shared LLM client at `src/core/llm-client.ts`.
 - Moved marketplace HTML to `docs/` with `css/` and `js/` assets; updated all script paths and README links.
+- Code snippet copy buttons now show a failure state if browser clipboard access is denied.
 
 ### Removed
 - Deleted legacy folders `01-Self-Healing-Tests`, `02-Smart-Data-Gen`, `03-Automated-Bug-Report`, `04-AI-Agents-QA`, `05-Visual-Regression`, and `lib/`.
diff --git a/README.md b/README.md
index 656889c2..f424a8e2 100644
--- a/README.md
+++ b/README.md
@@ -102,7 +102,7 @@ Fill in a form at `/submit` — name, system prompt, category, run command — a
 
 <img src="screenshots/cheatsheet.png" width="900" alt="Cheatsheet" />
 
-One-click copy reference with **10 collapsible sections** — all your go-to patterns in one place:
+One-click copy reference with **10 collapsible sections** — all your go-to patterns in one place. Copy buttons show a failure state if browser clipboard access is denied.
 
 | Section | Contents |
 |---------|----------|
diff --git a/ui/src/components/CodeSnippet.tsx b/ui/src/components/CodeSnippet.tsx
index 1b33ecea..ee413ae5 100644
--- a/ui/src/components/CodeSnippet.tsx
+++ b/ui/src/components/CodeSnippet.tsx
@@ -1,22 +1,35 @@
-import { useState } from 'react'
-import { useTranslation } from 'react-i18next'
-import ContentCopyIcon from '@mui/icons-material/ContentCopy'
-import CheckIcon from '@mui/icons-material/Check'
+import { useState } from 'react';
+import { useTranslation } from 'react-i18next';
+import ContentCopyIcon from '@mui/icons-material/ContentCopy';
+import CheckIcon from '@mui/icons-material/Check';
+import ErrorOutlinedIcon from '@mui/icons-material/ErrorOutlined';
 
 interface Props {
-  code: string
-  language?: string
+  code: string;
+  language?: string;
 }
 
 export default function CodeSnippet({ code, language }: Props) {
-  const { t } = useTranslation()
-  const [copied, setCopied] = useState(false)
+  const { t } = useTranslation();
+  const [copyStatus, setCopyStatus] = useState<'idle' | 'copied' | 'failed'>('idle');
 
   const handleCopy = async () => {
-    await navigator.clipboard.writeText(code)
-    setCopied(true)
-    setTimeout(() => setCopied(false), 2000)
-  }
+    try {
+      await navigator.clipboard.writeText(code);
+      setCopyStatus('copied');
+    } catch {
+      setCopyStatus('failed');
+    }
+
+    setTimeout(() => setCopyStatus('idle'), 2000);
+  };
+
+  const copyLabel =
+    copyStatus === 'copied'
+      ? t('common.copied')
+      : copyStatus === 'failed'
+        ? t('common.copy_failed')
+        : t('common.copy');
 
   return (
     // dir="ltr" — code is always left-to-right regardless of document language
@@ -37,15 +50,26 @@ export default function CodeSnippet({ code, language }: Props) {
         <button
           onClick={handleCopy}
           className="ms-auto flex items-center gap-1 text-xs px-2 py-0.5 rounded-lg hover:bg-sand-400 transition-colors"
-          style={{ color: 'var(--text-muted)' }}
+          style={{
+            color: copyStatus === 'failed' ? 'var(--coral-500, #ef4444)' : 'var(--text-muted)',
+          }}
         >
-          {copied ? <CheckIcon sx={{ fontSize: 12 }} /> : <ContentCopyIcon sx={{ fontSize: 12 }} />}
-          {copied ? t('common.copied') : t('common.copy')}
+          {copyStatus === 'copied' ? (
+            <CheckIcon sx={{ fontSize: 12 }} />
+          ) : copyStatus === 'failed' ? (
+            <ErrorOutlinedIcon sx={{ fontSize: 12 }} />
+          ) : (
+            <ContentCopyIcon sx={{ fontSize: 12 }} />
+          )}
+          {copyLabel}
         </button>
       </div>
-      <pre className="text-xs font-mono p-3 overflow-auto leading-relaxed" style={{ color: 'var(--text-main)' }}>
+      <pre
+        className="text-xs font-mono p-3 overflow-auto leading-relaxed"
+        style={{ color: 'var(--text-main)' }}
+      >
         {code}
       </pre>
     </div>
-  )
+  );
 }
diff --git a/ui/src/locales/en.json b/ui/src/locales/en.json
index 0ee05cdb..9754a8ce 100644
--- a/ui/src/locales/en.json
+++ b/ui/src/locales/en.json
@@ -16,6 +16,7 @@
   "common": {
     "copy": "Copy",
     "copied": "Copied!",
+    "copy_failed": "Failed to copy",
     "add_to_claude": "Add to Claude",
     "active": "Active",
     "planned": "Planned",
diff --git a/ui/src/locales/he.json b/ui/src/locales/he.json
index b5ff85b6..89d312ff 100644
--- a/ui/src/locales/he.json
+++ b/ui/src/locales/he.json
@@ -16,6 +16,7 @@
   "common": {
     "copy": "העתק",
     "copied": "הועתק!",
+    "copy_failed": "ההעתקה נכשלה",
     "add_to_claude": "הוסף לקלוד",
     "active": "פעיל",
     "planned": "מתוכנן",