diff --git a/app/static/app.js b/app/static/app.js
index 270d1ae..ff8704f 100644
--- a/app/static/app.js
+++ b/app/static/app.js
@@ -17,6 +17,7 @@
     modalKnownFiles: {},
     modalFileFilter: "",
     modalVisibleFiles: [],
+    modalSelectionAnchorPath: null,
     syncScrolling: false,
     settings: {
       set_file_date_to_first_aired_date: false,
@@ -755,6 +756,7 @@
       };
     });
     state.modalFileFilter = "";
+    state.modalSelectionAnchorPath = null;
     el.fileModalTitle.textContent = "File Discovery";
     el.modalAddSelectedFilesBtn.style.display = "";
     if (el.modalFileFilterInput) {
@@ -819,22 +821,62 @@
 
       const isSelected = state.modalSelectedFilePaths.has(file.path);
       if (isSelected) li.classList.add("selected");
+      if (state.modalSelectionAnchorPath && state.modalSelectionAnchorPath === file.path) {
+        li.classList.add("modal-anchor");
+      }
 
-      li.addEventListener("click", () => {
-        if (state.modalSelectedFilePaths.has(file.path)) {
-          state.modalSelectedFilePaths.delete(file.path);
-          li.classList.remove("selected");
-        } else {
-          state.modalSelectedFilePaths.add(file.path);
-          li.classList.add("selected");
-        }
-        updateModalSelectionCount();
+      li.addEventListener("click", (event) => {
+        handleModalFileRowClick(file.path, event);
       });
       el.modalFilesList.appendChild(li);
     });
     updateModalSelectionCount();
   }
 
+  function handleModalFileRowClick(path, event) {
+    const clickedPath = (path || "").toString().trim();
+    if (!clickedPath) return;
+
+    const visiblePaths = (state.modalVisibleFiles || [])
+      .map((f) => (f && f.path ? f.path : ""))
+      .filter((p) => p);
+    const isShift = !!(event && event.shiftKey);
+    const isToggle = !!(event && (event.ctrlKey || event.metaKey));
+
+    if (isShift) {
+      const anchor = state.modalSelectionAnchorPath || "";
+      const from = visiblePaths.indexOf(anchor);
+      const to = visiblePaths.indexOf(clickedPath);
+      if (from >= 0 && to >= 0) {
+        const start = Math.min(from, to);
+        const end = Math.max(from, to);
+        const rangePaths = visiblePaths.slice(start, end + 1);
+        state.modalSelectedFilePaths = new Set(rangePaths);
+      } else {
+        // Fallback: no valid anchor in current visible list.
+        state.modalSelectedFilePaths = new Set([clickedPath]);
+      }
+      state.modalSelectionAnchorPath = clickedPath;
+      renderModalFiles();
+      return;
+    }
+
+    if (isToggle) {
+      if (state.modalSelectedFilePaths.has(clickedPath)) {
+        state.modalSelectedFilePaths.delete(clickedPath);
+      } else {
+        state.modalSelectedFilePaths.add(clickedPath);
+      }
+      state.modalSelectionAnchorPath = clickedPath;
+      renderModalFiles();
+      return;
+    }
+
+    state.modalSelectedFilePaths = new Set([clickedPath]);
+    state.modalSelectionAnchorPath = clickedPath;
+    renderModalFiles();
+  }
+
   async function loadModalFiles(subpath) {
     const rootId = el.modalRootSelect.value;
     const chosenSubpath = (subpath || "").trim();
@@ -845,6 +887,7 @@
     const data = await api(
       `/api/files/discover?root_id=${encodeURIComponent(rootId)}&subpath=${encodeURIComponent(chosenSubpath)}&recursive=${recursive}&limit=200`
     );
+    state.modalSelectionAnchorPath = null;
     state.modalFiles = data.items || [];
     state.modalFiles.forEach((file) => {
       const path = file.path || "";
@@ -891,6 +934,7 @@
 
   function clearModalSelection() {
     state.modalSelectedFilePaths.clear();
+    state.modalSelectionAnchorPath = null;
     renderModalFiles();
   }
 
diff --git a/app/static/styles.css b/app/static/styles.css
index 0741c15..4198750 100644
--- a/app/static/styles.css
+++ b/app/static/styles.css
@@ -506,6 +506,10 @@ button.secondary {
   cursor: pointer;
 }
 
+#modalFilesList li.modal-anchor {
+  box-shadow: inset 0 0 0 1px var(--button-primary-border);
+}
+
 .modal-files-tools {
   margin-bottom: 8px;
 }
diff --git a/data/session_state.sqlite3 b/data/session_state.sqlite3
index b869528..bfdbd51 100644
Binary files a/data/session_state.sqlite3 and b/data/session_state.sqlite3 differ
diff --git a/feature_tests_file_modal_selection.sh b/feature_tests_file_modal_selection.sh
new file mode 100755
index 0000000..2f50a46
--- /dev/null
+++ b/feature_tests_file_modal_selection.sh
@@ -0,0 +1,44 @@
+#!/usr/bin/env bash
+set -euo pipefail
+
+BASE_URL="${BASE_URL:-http://127.0.0.1:8085}"
+ALT_BASE_URL="http://host.containers.internal:8085"
+
+detect_base_url() {
+  if curl -fsS --max-time 2 "$BASE_URL/api/health" >/dev/null 2>&1; then
+    echo "$BASE_URL"
+    return
+  fi
+  if curl -fsS --max-time 2 "$ALT_BASE_URL/api/health" >/dev/null 2>&1; then
+    echo "$ALT_BASE_URL"
+    return
+  fi
+  echo "$BASE_URL"
+}
+
+BASE_URL="$(detect_base_url)"
+echo "Using BASE_URL=$BASE_URL"
+
+echo "== Feature test 1: modal selection modifiers are implemented =="
+grep -q "modalSelectionAnchorPath" app/static/app.js || { echo "anchor state missing"; exit 1; }
+grep -q "event.shiftKey" app/static/app.js || { echo "shift handling missing"; exit 1; }
+grep -q "event.ctrlKey || event.metaKey" app/static/app.js || { echo "ctrl/meta handling missing"; exit 1; }
+echo "modifier selection validation passed"
+
+echo
+echo "== Feature test 2: anchor reset on clear and folder reload =="
+grep -q "state.modalSelectionAnchorPath = null;" app/static/app.js || { echo "anchor reset missing"; exit 1; }
+grep -q "function clearModalSelection()" app/static/app.js || { echo "clearModalSelection missing"; exit 1; }
+grep -q "async function loadModalFiles(subpath)" app/static/app.js || { echo "loadModalFiles missing"; exit 1; }
+echo "anchor reset validation passed"
+
+echo
+echo "== Feature test 3: modal file list UI still present with batch actions =="
+page="$(curl -fsS "$BASE_URL/")"
+echo "$page" | grep -q 'id="modalFilesList"' || { echo "modalFilesList missing"; exit 1; }
+echo "$page" | grep -q 'id="modalSelectAllFilesBtn"' || { echo "Select All button missing"; exit 1; }
+echo "$page" | grep -q 'id="modalClearSelectionBtn"' || { echo "Clear Selection button missing"; exit 1; }
+echo "modal UI validation passed"
+
+echo
+echo "All file modal selection feature tests passed."