diff --git a/index.html b/index.html
index 040d1b8..4f2dd6e 100644
--- a/index.html
+++ b/index.html
@@ -4,7 +4,63 @@
     <meta charset="UTF-8" />
     <link rel="icon" type="image/svg+xml" href="/onixbyte.svg" />
     <meta name="viewport" content="width=device-width, initial-scale=1.0" />
-    <title>DevLab</title>
+    
+    <!-- Primary Meta Tags -->
+    <title>DevLab - Free Developer Tools Collection</title>
+    <meta name="title" content="DevLab - Free Developer Tools Collection" />
+    <meta name="description" content="A collection of powerful, privacy-focused developer tools. JSON Viewer with JSONPath queries, BMI Calculator, and more. All processing happens locally in your browser." />
+    <meta name="keywords" content="developer tools, JSON viewer, JSONPath, BMI calculator, privacy-focused tools, free tools, online tools, JSON parser, JSON visualiser" />
+    <meta name="author" content="OnixByte" />
+    <meta name="robots" content="index, follow" />
+    <meta name="language" content="English" />
+    <meta name="revisit-after" content="7 days" />
+    
+    <!-- Open Graph / Facebook -->
+    <meta property="og:type" content="website" />
+    <meta property="og:url" content="https://dev-lab.onixbyte.dev/" />
+    <meta property="og:title" content="DevLab - Free Developer Tools Collection" />
+    <meta property="og:description" content="A collection of powerful, privacy-focused developer tools. JSON Viewer with JSONPath queries, BMI Calculator, and more. All processing happens locally in your browser." />
+    <meta property="og:image" content="https://dev-lab.onixbyte.dev/onixbyte.svg" />
+    <meta property="og:locale" content="en_GB" />
+    <meta property="og:site_name" content="DevLab" />
+    
+    <!-- Twitter -->
+    <meta property="twitter:card" content="summary_large_image" />
+    <meta property="twitter:url" content="https://dev-lab.onixbyte.dev/" />
+    <meta property="twitter:title" content="DevLab - Free Developer Tools Collection" />
+    <meta property="twitter:description" content="A collection of powerful, privacy-focused developer tools. JSON Viewer with JSONPath queries, BMI Calculator, and more." />
+    <meta property="twitter:image" content="https://dev-lab.onixbyte.dev/onixbyte.svg" />
+    
+    <!-- Canonical URL -->
+    <link rel="canonical" href="https://dev-lab.onixbyte.dev/" />
+    
+    <!-- Structured Data (JSON-LD) -->
+    <script type="application/ld+json">
+    {
+      "@context": "https://schema.org",
+      "@type": "WebApplication",
+      "name": "DevLab",
+      "description": "A collection of powerful, privacy-focused developer tools including JSON Viewer with JSONPath queries and BMI Calculator.",
+      "url": "https://dev-lab.onixbyte.dev",
+      "applicationCategory": "DeveloperApplication",
+      "operatingSystem": "Web Browser",
+      "offers": {
+        "@type": "Offer",
+        "price": "0",
+        "priceCurrency": "USD"
+      },
+      "featureList": [
+        "JSON Viewer with JSONPath queries",
+        "BMI Calculator",
+        "Privacy-focused local processing",
+        "Free and open source"
+      ],
+      "author": {
+        "@type": "Organization",
+        "name": "OnixByte"
+      }
+    }
+    </script>
   </head>
   <body>
     <div id="root"></div>
diff --git a/public/robots.txt b/public/robots.txt
new file mode 100644
index 0000000..b7b2ce7
--- /dev/null
+++ b/public/robots.txt
@@ -0,0 +1,10 @@
+# robots.txt for DevLab
+User-agent: *
+Allow: /
+
+# Sitemap location
+Sitemap: https://dev-lab.onixbyte.dev/sitemap.xml
+
+# Disallow admin or private areas if any
+# Disallow: /admin/
+# Disallow: /private/
diff --git a/public/sitemap.xml b/public/sitemap.xml
new file mode 100644
index 0000000..7dd0b5b
--- /dev/null
+++ b/public/sitemap.xml
@@ -0,0 +1,53 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<urlset xmlns="http://www.sitemaps.org/schemas/sitemap/0.9"
+        xmlns:xhtml="http://www.w3.org/1999/xhtml">
+  <!-- Homepage -->
+  <url>
+    <loc>https://dev-lab.onixbyte.dev/</loc>
+    <lastmod>2024-01-01</lastmod>
+    <changefreq>weekly</changefreq>
+    <priority>1.0</priority>
+    <xhtml:link rel="alternate" hreflang="en" href="https://dev-lab.onixbyte.dev/" />
+    <xhtml:link rel="alternate" hreflang="zh" href="https://dev-lab.onixbyte.dev/?lang=zh-CN" />
+  </url>
+  
+  <!-- JSON Viewer -->
+  <url>
+    <loc>https://dev-lab.onixbyte.dev/json-viewer</loc>
+    <lastmod>2024-01-01</lastmod>
+    <changefreq>monthly</changefreq>
+    <priority>0.9</priority>
+    <xhtml:link rel="alternate" hreflang="en" href="https://dev-lab.onixbyte.dev/json-viewer" />
+    <xhtml:link rel="alternate" hreflang="zh" href="https://dev-lab.onixbyte.dev/json-viewer?lang=zh-CN" />
+  </url>
+  
+  <!-- BMI Calculator -->
+  <url>
+    <loc>https://dev-lab.onixbyte.dev/bmi-calculator</loc>
+    <lastmod>2024-01-01</lastmod>
+    <changefreq>monthly</changefreq>
+    <priority>0.9</priority>
+    <xhtml:link rel="alternate" hreflang="en" href="https://dev-lab.onixbyte.dev/bmi-calculator" />
+    <xhtml:link rel="alternate" hreflang="zh" href="https://dev-lab.onixbyte.dev/bmi-calculator?lang=zh-CN" />
+  </url>
+  
+  <!-- About -->
+  <url>
+    <loc>https://dev-lab.onixbyte.dev/about</loc>
+    <lastmod>2024-01-01</lastmod>
+    <changefreq>monthly</changefreq>
+    <priority>0.7</priority>
+    <xhtml:link rel="alternate" hreflang="en" href="https://dev-lab.onixbyte.dev/about" />
+    <xhtml:link rel="alternate" hreflang="zh" href="https://dev-lab.onixbyte.dev/about?lang=zh-CN" />
+  </url>
+  
+  <!-- Contact -->
+  <url>
+    <loc>https://dev-lab.onixbyte.dev/contact</loc>
+    <lastmod>2024-01-01</lastmod>
+    <changefreq>monthly</changefreq>
+    <priority>0.6</priority>
+    <xhtml:link rel="alternate" hreflang="en" href="https://dev-lab.onixbyte.dev/contact" />
+    <xhtml:link rel="alternate" hreflang="zh" href="https://dev-lab.onixbyte.dev/contact?lang=zh-CN" />
+  </url>
+</urlset>
