diff --git a/src/app.js b/src/app.js
index 71903f7..22a3e7d 100644
--- a/src/app.js
+++ b/src/app.js
@@ -2486,6 +2486,19 @@
   pedZoomIn.addEventListener("click", () => pedZoomBy(0.2));
   pedZoomOut.addEventListener("click", () => pedZoomBy(-0.2));
   pedZoomReset.addEventListener("click", () => { pedZoom = 1; applyPedZoom(); });
+
+  // ---- collapse / expand all ----
+  const pedFoldAll = document.getElementById("ped-foldall");
+  function pedSetAll(collapsed) {
+    pedTree.querySelectorAll("li").forEach((li) => {
+      if (!li.querySelector(":scope > ul")) return; // no ancestors to fold
+      li.classList.toggle("collapsed", collapsed);
+      const t = li.querySelector(":scope > .ped-card > .ped-toggle");
+      if (t) t.textContent = collapsed ? "+" : "−";
+    });
+    pedFoldAll.textContent = collapsed ? "Expand all" : "Collapse all";
+  }
+  pedFoldAll.addEventListener("click", () => pedSetAll(pedFoldAll.textContent[0] === "C"));
   // Trackpad/desktop: ctrl or ⌘ + wheel zooms instead of scrolling the page.
   pedTree.addEventListener("wheel", (e) => {
     if (!e.ctrlKey && !e.metaKey) return;
@@ -2729,6 +2742,7 @@
     ul.className = "ped-tree-h";
     ul.append(root);
     pedTree.append(ul);
+    if (pedFoldAll) pedFoldAll.textContent = "Collapse all"; // fresh tree starts partly open
   }
 
   // Highlight (or unhighlight) every card that is the same dog as `key`.
diff --git a/src/changelog.json b/src/changelog.json
index 3c1cf1a..e282661 100644
--- a/src/changelog.json
+++ b/src/changelog.json
@@ -1,4 +1,5 @@
 [
+  { "date": "2026-07-26", "text": "Added a Collapse all / Expand all toggle to the pedigree, to fold the whole tree down to your dog or open every branch at once" },
   { "date": "2026-07-26", "text": "The pedigree is now zoomable — use the +/− buttons, ⌘/Ctrl-scroll, or pinch on a phone — to fit a wide tree on screen or zoom in for detail; your zoom level is remembered" },
   { "date": "2026-07-26", "text": "In the pedigree, a dog that fills more than one spot (pedigree collapse, common in a breed's older lines) now carries a ×N badge — tap it to highlight every place that dog appears in the tree" },
   { "date": "2026-07-26", "text": "The pedigree now reads top-down like a family tree — your dog on top with its sire and dam branching below — showing three generations at a glance, with each dog expandable to trace the line further back" },
diff --git a/src/index.html b/src/index.html
index 9ccd3c7..eeafed2 100644
--- a/src/index.html
+++ b/src/index.html
@@ -280,10 +280,13 @@
       <header class="pedigree-header">
         <button type="button" id="pedigree-back" class="ghost icon-btn" aria-label="Back to tracker" title="Back">←</button>
         <h1>🌳 Pedigree</h1>
-        <div class="ped-zoom" role="group" aria-label="Zoom">
-          <button type="button" id="ped-zoom-out" class="ghost icon-btn" aria-label="Zoom out" title="Zoom out">−</button>
-          <button type="button" id="ped-zoom-reset" class="ghost" aria-label="Reset zoom" title="Reset zoom">100%</button>
-          <button type="button" id="ped-zoom-in" class="ghost icon-btn" aria-label="Zoom in" title="Zoom in">+</button>
+        <div class="ped-controls">
+          <button type="button" id="ped-foldall" class="ghost">Collapse all</button>
+          <div class="ped-zoom" role="group" aria-label="Zoom">
+            <button type="button" id="ped-zoom-out" class="ghost icon-btn" aria-label="Zoom out" title="Zoom out">−</button>
+            <button type="button" id="ped-zoom-reset" class="ghost" aria-label="Reset zoom" title="Reset zoom">100%</button>
+            <button type="button" id="ped-zoom-in" class="ghost icon-btn" aria-label="Zoom in" title="Zoom in">+</button>
+          </div>
         </div>
       </header>
       <main class="pedigree-main">
diff --git a/src/style.css b/src/style.css
index 1a0b8ad..3f6d1f0 100644
--- a/src/style.css
+++ b/src/style.css
@@ -1065,9 +1065,17 @@ section.collapsed > :not(h2) { display: none; }
   gap: 10px;
   padding: 12px 4px 8px;
 }
+.pedigree-header { flex-wrap: wrap; }
 .pedigree-header h1 { font-size: 1.4rem; }
-.ped-zoom {
+.ped-controls {
   margin-left: auto;
+  display: flex;
+  align-items: center;
+  gap: 8px;
+  flex-shrink: 0;
+}
+#ped-foldall { padding: 5px 10px; font-size: 0.8rem; white-space: nowrap; }
+.ped-zoom {
   display: flex;
   align-items: center;
   gap: 4px;