diff --git a/package.json b/package.json
index d551a29..0b8bcf7 100644
--- a/package.json
+++ b/package.json
@@ -7,7 +7,7 @@
   "packageManager": "pnpm@11.5.2",
   "scripts": {
     "dev": "astro dev",
-    "build": "astro build",
+    "build": "astro build && pagefind --site dist",
     "preview": "astro preview",
     "migrate:blog": "node scripts/migrate-blog.mjs"
   },
@@ -23,5 +23,8 @@
   "repository": {
     "type": "git",
     "url": "https://github.com/codigosinsiesta/codigosinsiesta.github.io"
+  },
+  "devDependencies": {
+    "pagefind": "^1.5.2"
   }
 }
diff --git a/pnpm-lock.yaml b/pnpm-lock.yaml
index 21c8670..a2f5816 100644
--- a/pnpm-lock.yaml
+++ b/pnpm-lock.yaml
@@ -26,6 +26,10 @@ importers:
       svelte:
         specifier: ^5.45.5
         version: 5.56.3
+    devDependencies:
+      pagefind:
+        specifier: ^1.5.2
+        version: 1.5.2
 
 packages:
 
@@ -580,6 +584,41 @@ packages:
   '@oslojs/encoding@1.1.0':
     resolution: {integrity: sha512-70wQhgYmndg4GCPxPPxPGevRKqTIJ2Nh4OkiMWmDAVYsTQ+Ta7Sq+rPevXyXGdzr30/qZBnyOalCszoMxlyldQ==}
 
+  '@pagefind/darwin-arm64@1.5.2':
+    resolution: {integrity: sha512-MXpI+7HsAdPkvJ0gk9xj9g541BCqBZOBbdwj9g6lB5LCj6kSV6nqDSjzcAJwvOsfu0fjwvC8hQU+ecfhp+MpiQ==}
+    cpu: [arm64]
+    os: [darwin]
+
+  '@pagefind/darwin-x64@1.5.2':
+    resolution: {integrity: sha512-IojxFWMEJe0RQ7PQ3KXQsPIImNsbpPYpoZ+QUDrL8fAl/O27IX+LVLs74/UzEZy5uA2LD8Nz1AiwKr72vrkZQw==}
+    cpu: [x64]
+    os: [darwin]
+
+  '@pagefind/freebsd-x64@1.5.2':
+    resolution: {integrity: sha512-7EVzo9+0w+2cbe671BtMj10UlNo83I+HrLVLfRxO731svHRJKUfJ/mo05gU14pe9PCfpKNQT8FS3Xc/oDN6pOA==}
+    cpu: [x64]
+    os: [freebsd]
+
+  '@pagefind/linux-arm64@1.5.2':
+    resolution: {integrity: sha512-Ovt9+K35sqzn8H3ZMXGwls4TD/wMJuvRtShHIsmUQREmaxjrDEX7gHckRCrwYJ4XE1H1p6HkLz3wukrAnsfXQw==}
+    cpu: [arm64]
+    os: [linux]
+
+  '@pagefind/linux-x64@1.5.2':
+    resolution: {integrity: sha512-V+tFqHKXhQKq/WqPBD67AFy7scn1/aZID00ws4fSDd+1daSi5UHR9VVlRrOUYKxn3VuFQYRD7lYXdZK1WED1YA==}
+    cpu: [x64]
+    os: [linux]
+
+  '@pagefind/windows-arm64@1.5.2':
+    resolution: {integrity: sha512-hN9Nh90fNW61nNRCW9ZyQrAj/mD0eRvmJ8NlTUzkbuW8kIzGJUi3cxjFkEcMZ5h/8FsKWD/VcouZl4yo1F7B6g==}
+    cpu: [arm64]
+    os: [win32]
+
+  '@pagefind/windows-x64@1.5.2':
+    resolution: {integrity: sha512-Fa2Iyw7kaDRzGMfNYNUXNW2zbL5FQVDgSOcbDHdzBrDEdpqOqg8TcZ68F22ol6NJ9IGzvUdmeyZypLW5dyhqsg==}
+    cpu: [x64]
+    os: [win32]
+
   '@rollup/pluginutils@5.4.0':
     resolution: {integrity: sha512-MfPp06CjRLfXQ3wY0R8vJDYBy/MvVcc9OulEfR0B8Iv9ko+GCNaRZ+EpJYFl27LhKsZK0o420sYCRHCjfCgeUg==}
     engines: {node: '>=14.0.0'}
@@ -1399,6 +1438,10 @@ packages:
   package-manager-detector@1.6.0:
     resolution: {integrity: sha512-61A5ThoTiDG/C8s8UMZwSorAGwMJ0ERVGj2OjoW5pAalsNOg15+iQiPzrLJ4jhZ1HJzmC2PIHT2oEiH3R5fzNA==}
 
+  pagefind@1.5.2:
+    resolution: {integrity: sha512-XTUaK0hXMCu2jszWE584JGQT7y284TmMV9l/HX3rnG5uo3rHI/uHU56XTyyyPFjeWEBxECbAi0CaFDJOONtG0Q==}
+    hasBin: true
+
   parse-latin@7.0.0:
     resolution: {integrity: sha512-mhHgobPPua5kZ98EF4HWiH167JWBfl4pvAIXXdbaVohtK7a6YBOy56kvhCqduqyo/f3yrHFWmqmiMg/BkBkYYQ==}
 
@@ -1597,6 +1640,7 @@ packages:
   tsconfck@3.1.6:
     resolution: {integrity: sha512-ks6Vjr/jEw0P1gmOVwutM3B7fWxoWBL2KRDb1JfqGVawBmO5UsvmWOQFGHBPl5yxYz4eERr19E6L7NMv+Fej4w==}
     engines: {node: ^18 || >=20}
+    deprecated: unmaintained
     hasBin: true
     peerDependencies:
       typescript: ^5.0.0
@@ -2225,6 +2269,27 @@ snapshots:
 
   '@oslojs/encoding@1.1.0': {}
 
+  '@pagefind/darwin-arm64@1.5.2':
+    optional: true
+
+  '@pagefind/darwin-x64@1.5.2':
+    optional: true
+
+  '@pagefind/freebsd-x64@1.5.2':
+    optional: true
+
+  '@pagefind/linux-arm64@1.5.2':
+    optional: true
+
+  '@pagefind/linux-x64@1.5.2':
+    optional: true
+
+  '@pagefind/windows-arm64@1.5.2':
+    optional: true
+
+  '@pagefind/windows-x64@1.5.2':
+    optional: true
+
   '@rollup/pluginutils@5.4.0(rollup@4.61.1)':
     dependencies:
       '@types/estree': 1.0.9
@@ -3307,6 +3372,16 @@ snapshots:
 
   package-manager-detector@1.6.0: {}
 
+  pagefind@1.5.2:
+    optionalDependencies:
+      '@pagefind/darwin-arm64': 1.5.2
+      '@pagefind/darwin-x64': 1.5.2
+      '@pagefind/freebsd-x64': 1.5.2
+      '@pagefind/linux-arm64': 1.5.2
+      '@pagefind/linux-x64': 1.5.2
+      '@pagefind/windows-arm64': 1.5.2
+      '@pagefind/windows-x64': 1.5.2
+
   parse-latin@7.0.0:
     dependencies:
       '@types/nlcst': 2.0.3
diff --git a/src/pages/ensayos/[...slug].astro b/src/pages/ensayos/[...slug].astro
index d14bfab..6d217ee 100644
--- a/src/pages/ensayos/[...slug].astro
+++ b/src/pages/ensayos/[...slug].astro
@@ -19,13 +19,13 @@ const fmtFecha = (d: Date) =>
     <article class="section">
       <header style="max-width: 760px;">
         <p class="eyebrow">ensayo · {fmtFecha(post.data.fecha)}</p>
-        <h1 style="font-size: clamp(1.9rem, 4.5vw, 2.8rem);">{post.data.title}</h1>
-        <p class="meta">{post.data.autor}</p>
-        <p style="margin-top: 0.75rem;">
-          {post.data.tags.map((tag) => <span class="tag">{tag}</span>)}
+        <h1 style="font-size: clamp(1.9rem, 4.5vw, 2.8rem);" data-pagefind-meta="title">{post.data.title}</h1>
+        <p class="meta" data-pagefind-meta="autor">{post.data.autor}</p>
+        <p style="margin-top: 0.75rem;" data-pagefind-meta="tags">
+          {post.data.tags.map((tag) => <a href={`/ensayos/tags/${tag}`} class="tag">{tag}</a>)}
         </p>
       </header>
-      <div class="prose">
+      <div class="prose" data-pagefind-body>
         <Content />
       </div>
       <footer style="margin-top: 3.5rem; border-top: 1px solid var(--color-borde); padding-top: 1.5rem;">
diff --git a/src/pages/ensayos/index.astro b/src/pages/ensayos/index.astro
index 1e791e3..12ae74a 100644
--- a/src/pages/ensayos/index.astro
+++ b/src/pages/ensayos/index.astro
@@ -8,6 +8,15 @@ const ensayos = (await getCollection('ensayos')).sort(
 
 const fmtFecha = (d: Date) =>
   d.toLocaleDateString('es-ES', { year: 'numeric', month: 'short', day: '2-digit' });
+
+// Build tag counts, sorted by frequency
+const tagCounts = new Map<string, number>();
+for (const post of ensayos) {
+  for (const tag of post.data.tags) {
+    tagCounts.set(tag, (tagCounts.get(tag) || 0) + 1);
+  }
+}
+const sortedTags = Array.from(tagCounts.entries()).sort((a, b) => b[1] - a[1]);
 ---
 
 <Base
@@ -16,17 +25,35 @@ const fmtFecha = (d: Date) =>
   activeHref="/ensayos"
 >
   <div class="container">
-    <section class="section">
+    <section class="section" data-csi-essay-list>
       <p class="eyebrow">artículos</p>
       <h1>Artículos</h1>
       <p class="lead" style="max-width: 40rem;">
         Claims fuertes con evidencia al lado. Lo que aprendemos construyendo en público, escrito
         para que te sirva.
       </p>
-      <ul class="item-list" style="margin-top: 2rem;">
+
+      <!-- Search bar (Pagefind) -->
+      <div id="search" class="search-bar" style="margin-top: 1.75rem;"></div>
+
+      <!-- Tag filter bar -->
+      <nav class="tag-cloud" aria-label="Filtrar por tema" style="margin-top: 1.75rem;" data-csi-tag-cloud>
+        <button class="tag tag--active" data-csi-tag="*" type="button">todos</button>
+        {
+          sortedTags.map(([tag, count]) => (
+            <button class="tag" data-csi-tag={tag} type="button">{tag}<sup>{count}</sup></button>
+          ))
+        }
+      </nav>
+
+      <p class="meta" style="margin-top: 1rem;" data-csi-filter-info>
+        Mostrando {ensayos.length} artículo{ensayos.length !== 1 ? 's' : ''}
+      </p>
+
+      <ul class="item-list" style="margin-top: 1.5rem;" data-csi-item-container>
         {
           ensayos.map((post) => (
-            <li>
+            <li data-csi-item data-tags={JSON.stringify(post.data.tags)}>
               <p class="meta">
                 {fmtFecha(post.data.fecha)} · {post.data.autor}
               </p>
@@ -35,8 +62,8 @@ const fmtFecha = (d: Date) =>
               </h3>
               <p>{post.data.description}</p>
               <p style="margin-top: 0.6rem; margin-bottom: 0;">
-                {post.data.tags.slice(0, 4).map((tag) => (
-                  <span class="tag">{tag}</span>
+                {post.data.tags.map((tag) => (
+                  <a href={`/ensayos/tags/${tag}`} class="tag" data-csi-tag-link={tag}>{tag}</a>
                 ))}
               </p>
             </li>
@@ -46,3 +73,182 @@ const fmtFecha = (d: Date) =>
     </section>
   </div>
 </Base>
+
+<script is:inline>
+  // ── Pagefind search (dynamic load — only exists after build) ──
+  (function() {
+    const script = document.createElement('script');
+    script.src = '/pagefind/pagefind-ui.js';
+    script.onload = function() {
+      new PagefindUI({
+        element: "#search",
+        showImages: false,
+        showSubResults: false,
+        pageSize: 8,
+        translations: {
+          placeholder: "Buscar por título, tag o contenido…",
+        },
+      });
+    };
+    // Load CSS too
+    const link = document.createElement('link');
+    link.rel = 'stylesheet';
+    link.href = '/pagefind/pagefind-ui.css';
+    document.head.appendChild(link);
+    document.head.appendChild(script);
+  })();
+
+  // ── Client-side tag filter ──
+  function initTagFilter() {
+    const cloud = document.querySelector('[data-csi-tag-cloud]');
+    const items = document.querySelectorAll('[data-csi-item]');
+    const info = document.querySelector('[data-csi-filter-info]');
+    if (!cloud || !items.length) return;
+
+    let activeTag = '*';
+
+    function applyFilter(tag) {
+      activeTag = tag;
+      let visible = 0;
+
+      items.forEach((el) => {
+        let tags = [];
+        try { tags = JSON.parse(el.getAttribute('data-tags') || '[]'); } catch (_) {}
+        const match = tag === '*' || tags.includes(tag);
+        el.style.display = match ? '' : 'none';
+        if (match) visible++;
+      });
+
+      // Update active button
+      cloud.querySelectorAll('[data-csi-tag]').forEach((btn) => {
+        const t = btn.getAttribute('data-csi-tag');
+        btn.classList.toggle('tag--active', t === tag);
+      });
+
+      // Update count
+      if (info) {
+        const word = visible === 1 ? 'artículo' : 'artículos';
+        const label = tag === '*'
+          ? `Mostrando ${visible} ${word}`
+          : `Mostrando ${visible} ${word} con <strong>«${tag}»</strong>`;
+        info.innerHTML = label;
+      }
+
+      // Update URL without reload
+      const url = tag === '*' ? '/ensayos' : `/ensayos/tags/${tag}`;
+      if (window.location.pathname !== url) {
+        window.history.replaceState({ tag }, '', url);
+      }
+    }
+
+    // Click on tag cloud buttons
+    cloud.addEventListener('click', (e) => {
+      const btn = e.target.closest('[data-csi-tag]');
+      if (!btn) return;
+      e.preventDefault();
+      const tag = btn.getAttribute('data-csi-tag');
+      if (tag) applyFilter(tag);
+    });
+
+    // Click on tag links inside items → trigger filter instead of navigating
+    document.addEventListener('click', (e) => {
+      const link = e.target.closest('[data-csi-tag-link]');
+      if (!link) return;
+      const tag = link.getAttribute('data-csi-tag-link');
+      if (tag) {
+        e.preventDefault();
+        applyFilter(tag);
+        // Scroll to tag cloud so user sees the active filter
+        cloud.scrollIntoView({ behavior: 'smooth', block: 'start' });
+      }
+    });
+
+    // Restore filter from URL on page load
+    const pathMatch = window.location.pathname.match(/^\/ensayos\/tags\/(.+?)(\/index\.html)?\/?$/);
+    if (pathMatch) {
+      const tagFromUrl = decodeURIComponent(pathMatch[1]);
+      // Verify the tag exists in the cloud
+      const exists = cloud.querySelector(`[data-csi-tag="${CSS.escape(tagFromUrl)}"]`);
+      if (exists) applyFilter(tagFromUrl);
+    }
+  }
+
+  initTagFilter();
+</script>
+
+<style>
+  .search-bar {
+    max-width: 520px;
+  }
+
+  /* Pagefind UI overrides for the dark blueprint theme */
+  .search-bar :global(.pagefind-ui__search-input) {
+    font-family: var(--font-body);
+    font-size: 0.95rem;
+    padding: 0.65rem 0.9rem;
+    border-radius: var(--radius-sm);
+    border: 1px solid var(--color-borde2);
+    background: var(--color-fondo-elev);
+    color: var(--color-tinta);
+    width: 100%;
+    outline: none;
+    transition: border-color var(--transition-fast);
+  }
+
+  .search-bar :global(.pagefind-ui__search-input:focus) {
+    border-color: var(--color-cielo);
+    box-shadow: 0 0 0 3px rgba(96, 165, 250, 0.15);
+  }
+
+  .search-bar :global(.pagefind-ui__search-input::placeholder) {
+    color: var(--color-tinta3);
+  }
+
+  .search-bar :global(.pagefind-ui__result) {
+    padding: 1rem 0;
+    border-bottom: 1px solid var(--color-borde);
+  }
+
+  .search-bar :global(.pagefind-ui__result-title) {
+    font-family: var(--font-display);
+    font-weight: 700;
+    font-size: 1.05rem;
+  }
+
+  .search-bar :global(.pagefind-ui__result-title a) {
+    color: var(--color-tinta);
+  }
+
+  .search-bar :global(.pagefind-ui__result-title a):hover {
+    color: var(--color-cielo);
+    text-decoration: none;
+  }
+
+  .search-bar :global(.pagefind-ui__result-excerpt) {
+    font-size: 0.9rem;
+    color: var(--color-tinta2);
+    margin-top: 0.3rem;
+    line-height: 1.5;
+  }
+
+  .search-bar :global(.pagefind-ui__result-excerpt mark) {
+    background: rgba(96, 165, 250, 0.25);
+    color: var(--color-cielo);
+    border-radius: 2px;
+    padding: 0 2px;
+  }
+
+  .search-bar :global(.pagefind-ui__button) {
+    font-family: var(--font-body);
+    border-radius: var(--radius-sm);
+    border: 1px solid var(--color-borde);
+    background: var(--color-fondo-elev);
+    color: var(--color-tinta);
+    cursor: pointer;
+  }
+
+  .search-bar :global(.pagefind-ui__message) {
+    font-size: 0.85rem;
+    color: var(--color-tinta3);
+  }
+</style>
diff --git a/src/pages/ensayos/tags/[tag].astro b/src/pages/ensayos/tags/[tag].astro
new file mode 100644
index 0000000..ee71c55
--- /dev/null
+++ b/src/pages/ensayos/tags/[tag].astro
@@ -0,0 +1,72 @@
+---
+import Base from '../../../layouts/Base.astro';
+import { getCollection } from 'astro:content';
+
+export async function getStaticPaths() {
+  const ensayos = await getCollection('ensayos');
+  const allTags = new Set<string>();
+  for (const post of ensayos) {
+    for (const tag of post.data.tags) {
+      allTags.add(tag);
+    }
+  }
+  return Array.from(allTags).map((tag) => ({ params: { tag }, props: { tag } }));
+}
+
+const { tag } = Astro.props;
+
+const ensayos = (await getCollection('ensayos'))
+  .filter((p) => p.data.tags.includes(tag))
+  .sort((a, b) => b.data.fecha.valueOf() - a.data.fecha.valueOf());
+
+const fmtFecha = (d: Date) =>
+  d.toLocaleDateString('es-ES', { year: 'numeric', month: 'short', day: '2-digit' });
+---
+
+<Base
+  title={`Artículos sobre "${tag}"`}
+  description={`Artículos de Código Sin Siesta etiquetados con "${tag}".`}
+  activeHref="/ensayos"
+>
+  <div class="container">
+    <section class="section">
+      <p class="eyebrow">artículos</p>
+      <h1>Artículos sobre <span class="hl">«{tag}»</span></h1>
+      <p class="lead" style="max-width: 40rem;">
+        {ensayos.length} artículo{ensayos.length !== 1 ? 's' : ''} etiquetado{ensayos.length !== 1 ? 's' : ''} con <strong>{tag}</strong>.
+        <a href="/ensayos" style="margin-left: 1rem; font-size: 0.9rem;">← Ver todos</a>
+      </p>
+      {
+        ensayos.length === 0 ? (
+          <p style="margin-top: 2rem; color: var(--color-tinta3);">
+            No hay artículos con este tag todavía.
+          </p>
+        ) : (
+          <ul class="item-list" style="margin-top: 2rem;">
+            {ensayos.map((post) => (
+              <li>
+                <p class="meta">
+                  {fmtFecha(post.data.fecha)} · {post.data.autor}
+                </p>
+                <h3>
+                  <a href={`/ensayos/${post.id}`}>{post.data.title}</a>
+                </h3>
+                <p>{post.data.description}</p>
+                <p style="margin-top: 0.6rem; margin-bottom: 0;">
+                  {post.data.tags.map((t) => (
+                    <a
+                      href={`/ensayos/tags/${t}`}
+                      class:list={['tag', { 'tag--active': t === tag }]}
+                    >
+                      {t}
+                    </a>
+                  ))}
+                </p>
+              </li>
+            ))}
+          </ul>
+        )
+      }
+    </section>
+  </div>
+</Base>
diff --git a/src/styles/site.css b/src/styles/site.css
index 9575189..a16fad5 100644
--- a/src/styles/site.css
+++ b/src/styles/site.css
@@ -131,6 +131,52 @@ a.card:hover {
   border: 1px solid var(--color-borde);
   color: var(--color-tinta3);
   margin-right: 0.4rem;
+  margin-bottom: 0.35rem;
+  text-decoration: none;
+  transition: border-color var(--transition-fast), color var(--transition-fast),
+    background var(--transition-fast);
+}
+
+/* Reset button defaults when .tag is a <button> */
+button.tag {
+  background: transparent;
+  cursor: pointer;
+  font-family: var(--font-mono);
+  line-height: inherit;
+}
+
+a.tag:hover,
+button.tag:hover {
+  text-decoration: none;
+  border-color: var(--color-cielo);
+  color: var(--color-cielo);
+  background: var(--color-accent-soft);
+}
+
+.tag--active {
+  border-color: var(--color-cielo);
+  color: var(--color-cielo);
+  background: var(--color-accent-soft);
+}
+
+.tag sup {
+  font-size: 0.65em;
+  color: var(--color-tinta3);
+  margin-left: 0.15em;
+  vertical-align: super;
+}
+
+/* tag cloud / filter bar */
+.tag-cloud {
+  display: flex;
+  flex-wrap: wrap;
+  gap: 0.25rem;
+  align-items: center;
+}
+
+.tag-cloud .tag {
+  font-size: 0.72rem;
+  padding: 0.2rem 0.7rem;
 }
 
 .badge {