diff --git a/app/react-components/devtools/tiles.jsx b/app/react-components/devtools/tiles.jsx
index a81dbc1..3b9db65 100644
--- a/app/react-components/devtools/tiles.jsx
+++ b/app/react-components/devtools/tiles.jsx
@@ -11,6 +11,7 @@ export default function Tiles({eventsChannel}) {
   const wrapperRef = useRef();
   const imageRef = useRef();
   const imageRect = useRect(imageRef);
+  const [indices, setIndices] = useState([]);
   const [selection, setSelection] = useState({x: 0, y: 0, w: 1, h: 1});
   const [moveStart, setMoveStart] = useState();
   const [layer, setLayer] = useState(0);
@@ -35,17 +36,19 @@ export default function Tiles({eventsChannel}) {
       if (at.x < 0 || at.y < 0 || at.x >= area.x || at.y >= area.y) {
         return;
       }
-      const payload = {
-        brush,
-        layer,
-        stamp: {
-          at,
-          data: stamp,
-        },
-      }
       client.send({
         type: 'AdminAction',
-        payload: {type: 'paint', value: payload},
+        payload: {
+          type: 'paint',
+          value: {
+            brush,
+            layer,
+            stamp: {
+              at,
+              data: stamp,
+            },
+          },
+        },
       });
     }
     eventsChannel.addListener('click', onClick);
@@ -64,6 +67,7 @@ export default function Tiles({eventsChannel}) {
   const {sourceJson, tileSize} = TileLayers.layer(0);
   const {w, h} = sourceJson.meta.size;
   const factor = (imageRect?.width ?? 1) / w;
+  const wt = w / tileSize.x;
   return (
     <div className={styles.tiles}>
       <form>
@@ -125,8 +129,13 @@ export default function Tiles({eventsChannel}) {
           const y = Math.floor((c.y - top) / (tileSize.y * factor));
           setMoveStart({x, y});
           setSelection({x, y, w: 1, h: 1});
+          setIndices([y * wt + x]);
         }}
         onMouseMove={(event) => {
+          if (0 === event.buttons) {
+            setMoveStart();
+            return;
+          }
           if (!moveStart) {
             return;
           }
@@ -145,12 +154,24 @@ export default function Tiles({eventsChannel}) {
           );
           const mx = Math.min(sx, x);
           const my = Math.min(sy, y);
-          setSelection({x: mx, y: my, w: Math.abs(sx - x) + 1, h: Math.abs(sy - y) + 1});
-        }}
-        onMouseUp={() => {
-          setMoveStart();
+          const sw = Math.abs(sx - x) + 1;
+          const sh = Math.abs(sy - y) + 1;
+          const newSelection = {
+            x: mx,
+            y: my,
+            w: sw,
+            h: sh,
+          };
+          if (
+            selection.x === newSelection.x
+            && selection.y === newSelection.y
+            && selection.w === newSelection.w
+            && selection.h === newSelection.h
+          ) {
+            return;
+          }
+          setSelection(newSelection);
           const stamp = [];
-          const {x, y, w: sw, h: sh} = selection;
           const tw = w / tileSize.x;
           for (let iy = 0; iy < sh; ++iy) {
             const row = [];
@@ -160,6 +181,13 @@ export default function Tiles({eventsChannel}) {
             stamp.push(row);
           }
           setStamp(stamp);
+          const indices = [];
+          for (let sy = 0; sy < selection.h; ++sy) {
+            for (let sx = 0; sx < selection.w; ++sx) {
+              indices.push(((selection.y + sy) * wt) + (selection.x + sx));
+            }
+          }
+          setIndices(indices);
         }}
         className={styles.selectionWrapper}
         ref={wrapperRef}
@@ -179,6 +207,25 @@ export default function Tiles({eventsChannel}) {
           src={TileLayers.layer(0).source.replace('.json', '.png')}
         />
       </div>
+      <div
+        className={styles.status}
+      >
+        <code className={styles.selectionStatus}>
+          Sel:
+          {' {'}
+          {selection.x}{', '}
+          {selection.y}{', '}
+          {selection.w}{', '}
+          {selection.h}
+          {'}'}
+        </code>
+        <code>
+          Idx:
+          {' ['}
+          {indices.join(', ')}
+          {']'}
+        </code>
+      </div>
     </div>
   );
 }
\ No newline at end of file
diff --git a/app/react-components/devtools/tiles.module.css b/app/react-components/devtools/tiles.module.css
index 8d62aa2..34fa719 100644
--- a/app/react-components/devtools/tiles.module.css
+++ b/app/react-components/devtools/tiles.module.css
@@ -28,3 +28,16 @@
   background-color: #ffffff44;
   position: absolute;
 }
+
+.status {
+  align-items: end;
+  display: flex;
+  font-size: 0.6rem;
+  gap: 32px;
+  justify-content: space-between;
+  margin: 8px;
+}
+
+.selectionStatus {
+  white-space: nowrap;
+}