diff --git a/unredact/static/dom.js b/unredact/static/dom.js
index 7f26a2f..9c7383d 100644
--- a/unredact/static/dom.js
+++ b/unredact/static/dom.js
@@ -12,6 +12,7 @@ export const pageInfo = document.getElementById("page-info");
 export const prevBtn = /** @type {HTMLButtonElement} */ (document.getElementById("prev-page"));
 export const nextBtn = /** @type {HTMLButtonElement} */ (document.getElementById("next-page"));
 export const redactionListEl = document.getElementById("redaction-list");
+export const detectBtn = /** @type {HTMLButtonElement} */ (document.getElementById("detect-btn"));
 export const zoomInBtn = document.getElementById("zoom-in");
 export const zoomOutBtn = document.getElementById("zoom-out");
 export const zoomFitBtn = document.getElementById("zoom-fit");
diff --git a/unredact/static/index.html b/unredact/static/index.html
index 634f0c4..70aa01a 100644
--- a/unredact/static/index.html
+++ b/unredact/static/index.html
@@ -34,6 +34,7 @@
 
       <div id="workspace">
         <div id="left-panel">
+          <button id="detect-btn" disabled>Detect Redactions</button>
           <div id="redaction-list"></div>
         </div>
 
diff --git a/unredact/static/main.js b/unredact/static/main.js
index 4a72fc1..6027f0c 100644
--- a/unredact/static/main.js
+++ b/unredact/static/main.js
@@ -4,7 +4,7 @@
 import { state } from './state.js';
 import {
   dropZone, fileInput, uploadSection, viewerSection, docImage,
-  canvas, pageInfo, prevBtn, nextBtn, redactionListEl,
+  canvas, pageInfo, prevBtn, nextBtn, redactionListEl, detectBtn,
   rightPanel, fontSelect,
   solveAccept, gapValue, showToast,
 } from './dom.js';
@@ -96,8 +96,8 @@ async function uploadFile(file) {
   // Load the first page image and controls immediately
   await loadPage(1);
 
-  // Start background analysis via SSE
-  startAnalysisSSE();
+  // Start background OCR via SSE
+  startOcrSSE();
 }
 
 /**
@@ -120,12 +120,51 @@ function startAnalysisSSE() {
     } else if (data.event === "done") {
       es.close();
       showToast("Analysis complete");
+      if (detectBtn) {
+        detectBtn.disabled = false;
+        detectBtn.textContent = "Detect Redactions";
+      }
     }
   });
 
   es.addEventListener("error", () => {
     es.close();
     showToast("Analysis connection lost", "error");
+    if (detectBtn) {
+      detectBtn.disabled = false;
+      detectBtn.textContent = "Detect Redactions";
+    }
+  });
+}
+
+function startOcrSSE() {
+  const es = new EventSource(`/api/doc/${state.docId}/ocr`);
+  showToast("Running OCR...", "info");
+
+  es.onmessage = (e) => {
+    const data = JSON.parse(e.data);
+    if (data.event === "page_ocr_complete") {
+      // OCR cached for this page on the backend
+    } else if (data.event === "ocr_complete") {
+      es.close();
+      state.ocrReady = true;
+      showToast("OCR complete — ready to detect redactions", "success");
+      if (detectBtn) detectBtn.disabled = false;
+    } else if (data.event === "error") {
+      showToast(`OCR error on page ${data.page}: ${data.message}`, "error");
+    }
+  };
+  es.onerror = () => {
+    es.close();
+    showToast("OCR connection lost", "error");
+  };
+}
+
+if (detectBtn) {
+  detectBtn.addEventListener("click", () => {
+    detectBtn.disabled = true;
+    detectBtn.textContent = "Detecting...";
+    startAnalysisSSE();
   });
 }
 
diff --git a/unredact/static/state.js b/unredact/static/state.js
index 312a031..48ca08b 100644
--- a/unredact/static/state.js
+++ b/unredact/static/state.js
@@ -10,6 +10,7 @@ export const state = {
   activeRedaction: null,
   fonts: [],
   fontsReady: false,
+  ocrReady: false,
   zoom: 1,
   panX: 0,
   panY: 0,
diff --git a/unredact/static/style.css b/unredact/static/style.css
index ee3d8aa..55f74dd 100644
--- a/unredact/static/style.css
+++ b/unredact/static/style.css
@@ -147,6 +147,25 @@ main {
   padding: 0.5rem 0;
 }
 
+#detect-btn {
+  width: 100%;
+  padding: 8px 12px;
+  margin-bottom: 8px;
+  background: #2563eb;
+  color: white;
+  border: none;
+  border-radius: 4px;
+  cursor: pointer;
+  font-size: 14px;
+}
+#detect-btn:hover:not(:disabled) {
+  background: #1d4ed8;
+}
+#detect-btn:disabled {
+  opacity: 0.5;
+  cursor: not-allowed;
+}
+
 /* Redaction list items */
 .redaction-item {
   padding: 0.5rem 0.75rem;