diff --git a/Makefile b/Makefile
index efbc20f..91aaf90 100644
--- a/Makefile
+++ b/Makefile
@@ -1,5 +1,5 @@
 BINARY=syncserver
-VERSION?=1.0.10
+VERSION?=1.0.11
 GO?=go
 LDFLAGS=-s -w -X main.version=$(VERSION) -X main.commit=$(shell git rev-parse --short HEAD 2>/dev/null || echo unknown)
 BUILD_FLAGS=CGO_ENABLED=0
diff --git a/cmd/server/main.go b/cmd/server/main.go
index e692697..91ed5d4 100644
--- a/cmd/server/main.go
+++ b/cmd/server/main.go
@@ -20,7 +20,7 @@ import (
 	"github.com/syncserver/internal/syncengine"
 )
 
-var version = "1.0.10"
+var version = "1.0.11"
 
 func main() {
 	cfgPath := flag.String("config", "", "Path to config.yaml")
diff --git a/internal/api/handlers_machines.go b/internal/api/handlers_machines.go
index 8d398a3..ca14648 100644
--- a/internal/api/handlers_machines.go
+++ b/internal/api/handlers_machines.go
@@ -10,15 +10,17 @@ import (
 
 	"github.com/go-chi/chi/v5"
 	"github.com/syncserver/internal/models"
+	"github.com/syncserver/internal/syncengine"
 	"github.com/syncserver/internal/wol"
 )
 
 type MachineHandler struct {
-	db *sql.DB
+	db     *sql.DB
+	engine *syncengine.Engine
 }
 
-func NewMachineHandler(db *sql.DB) *MachineHandler {
-	return &MachineHandler{db: db}
+func NewMachineHandler(db *sql.DB, engine *syncengine.Engine) *MachineHandler {
+	return &MachineHandler{db: db, engine: engine}
 }
 
 var macRegex = regexp.MustCompile(`^([0-9A-Fa-f]{2}[:-]){5}[0-9A-Fa-f]{2}$`)
@@ -209,6 +211,16 @@ func (h *MachineHandler) TestWoL(w http.ResponseWriter, r *http.Request) {
 	writeJSON(w, map[string]interface{}{"ok": true, "sent": 3})
 }
 
+func (h *MachineHandler) Refresh(w http.ResponseWriter, r *http.Request) {
+	if h.engine == nil {
+		writeError(w, http.StatusInternalServerError, "engine not available")
+		return
+	}
+	go h.engine.ProbeAllMachines()
+	w.WriteHeader(http.StatusAccepted)
+	writeJSON(w, map[string]string{"status": "probing"})
+}
+
 func (h *MachineHandler) Delete(w http.ResponseWriter, r *http.Request) {
 	id, err := strconv.ParseInt(chi.URLParam(r, "id"), 10, 64)
 	if err != nil {
diff --git a/internal/api/router.go b/internal/api/router.go
index cbd3c1e..7b691f1 100644
--- a/internal/api/router.go
+++ b/internal/api/router.go
@@ -33,7 +33,7 @@ func NewServer(cfg *config.Config, db *sql.DB, engine *syncengine.Engine) *Serve
 	s := &Server{router: r, cfg: cfg, engine: engine}
 
 	authHandler := NewAuthHandler(db)
-	machineHandler := NewMachineHandler(db)
+	machineHandler := NewMachineHandler(db, engine)
 	syncPairHandler := NewSyncPairHandler(db)
 	jobHandler := NewJobHandler(db, engine)
 	sseHandler := NewSSEHandler(engine)
@@ -49,6 +49,7 @@ func NewServer(cfg *config.Config, db *sql.DB, engine *syncengine.Engine) *Serve
 		r.With(auth.RequireAuth).Route("/machines", func(r chi.Router) {
 			r.Get("/", machineHandler.List)
 			r.Post("/", machineHandler.Create)
+			r.Post("/refresh", machineHandler.Refresh)
 			r.Get("/{id}", machineHandler.Get)
 			r.Put("/{id}", machineHandler.Update)
 			r.Delete("/{id}", machineHandler.Delete)
diff --git a/internal/syncengine/engine.go b/internal/syncengine/engine.go
index 45c3a2a..b4a4915 100644
--- a/internal/syncengine/engine.go
+++ b/internal/syncengine/engine.go
@@ -17,12 +17,13 @@ import (
 )
 
 type Engine struct {
-	db       *sql.DB
-	cfg      *config.Config
-	queue    *Queue
-	eventBus *EventBus
-	mu       sync.RWMutex
-	stopped  bool
+	db           *sql.DB
+	cfg          *config.Config
+	queue        *Queue
+	eventBus     *EventBus
+	mu           sync.RWMutex
+	stopped      bool
+	lastProbeAt  atomic.Int64
 }
 
 type Event struct {
@@ -333,3 +334,51 @@ func (e *Engine) CreateJob(syncPairID int64, triggerType string) (int64, error)
 	}
 	return id, nil
 }
+
+const (
+	probeThrottleSeconds = 10
+	probeTimeout         = 1500 * time.Millisecond
+	probeMaxConcurrent   = 20
+)
+
+func (e *Engine) ProbeAllMachines() {
+	now := time.Now().UnixNano()
+	last := e.lastProbeAt.Load()
+
+	if now-last < int64(probeThrottleSeconds*time.Second) {
+		slog.Debug("ProbeAllMachines: skipped (throttled)")
+		return
+	}
+	if !e.lastProbeAt.CompareAndSwap(last, now) {
+		return
+	}
+
+	machineRepo := models.NewMachineRepository(e.db)
+	ms, err := machineRepo.GetAll()
+	if err != nil {
+		slog.Warn("ProbeAllMachines: list failed", "error", err)
+		return
+	}
+
+	sem := make(chan struct{}, probeMaxConcurrent)
+	var wg sync.WaitGroup
+
+	for i := range ms {
+		wg.Add(1)
+		sem <- struct{}{}
+		go func(m *models.Machine) {
+			defer wg.Done()
+			defer func() { <-sem }()
+
+			ctx, cancel := context.WithTimeout(context.Background(), probeTimeout)
+			defer cancel()
+
+			status := "offline"
+			if wol.IsReachable(ctx, m.Host, m.Port, probeTimeout) {
+				status = "online"
+			}
+			e.setMachineStatus(m.ID, status)
+		}(&ms[i])
+	}
+	wg.Wait()
+}
diff --git a/internal/syncengine/engine_status_test.go b/internal/syncengine/engine_status_test.go
index a4f8037..cdeca8f 100644
--- a/internal/syncengine/engine_status_test.go
+++ b/internal/syncengine/engine_status_test.go
@@ -3,6 +3,7 @@ package syncengine
 import (
 	"context"
 	"net"
+	"sync/atomic"
 	"testing"
 	"time"
 
@@ -37,3 +38,29 @@ func TestIsReachableTimeout(t *testing.T) {
 		t.Errorf("IsReachable returned too early: %v", d)
 	}
 }
+
+func TestProbeThrottle(t *testing.T) {
+	e := &Engine{lastProbeAt: atomic.Int64{}}
+
+	e.lastProbeAt.Store(time.Now().UnixNano())
+
+	now := time.Now().UnixNano()
+	last := e.lastProbeAt.Load()
+	if now-last < int64(probeThrottleSeconds*time.Second) {
+		return
+	}
+	t.Error("throttle check did not run as expected")
+}
+
+func TestProbeConstants(t *testing.T) {
+	if probeThrottleSeconds != 10 {
+		t.Errorf("probeThrottleSeconds = %d, want 10", probeThrottleSeconds)
+	}
+	if probeTimeout != 1500*time.Millisecond {
+		t.Errorf("probeTimeout = %v, want 1500ms", probeTimeout)
+	}
+	if probeMaxConcurrent != 20 {
+		t.Errorf("probeMaxConcurrent = %d, want 20", probeMaxConcurrent)
+	}
+}
+
diff --git a/web/src/pages/Dashboard.tsx b/web/src/pages/Dashboard.tsx
index 50efecd..aac268c 100644
--- a/web/src/pages/Dashboard.tsx
+++ b/web/src/pages/Dashboard.tsx
@@ -32,6 +32,7 @@ export default function Dashboard() {
       })
       .catch(() => {})
       .finally(() => setLoading(false));
+    api('/api/machines/refresh', { method: 'POST' }).catch(() => {});
   }, []);
 
   useEffect(() => {
diff --git a/web/src/pages/Machines.tsx b/web/src/pages/Machines.tsx
index d534e53..e8c185c 100644
--- a/web/src/pages/Machines.tsx
+++ b/web/src/pages/Machines.tsx
@@ -66,9 +66,14 @@ export default function Machines() {
   const [deleteId, setDeleteId] = useState<number | null>(null);
   const [form, setForm] = useState<MachineForm>(defaultForm);
   const [loading, setLoading] = useState(false);
+  const [probing, setProbing] = useState(false);
 
   useEffect(() => {
     load();
+    setProbing(true);
+    api('/api/machines/refresh', { method: 'POST' }).catch(() => {});
+    const timer = setTimeout(() => setProbing(false), 5000);
+    return () => clearTimeout(timer);
   }, []);
 
   useEffect(() => {
@@ -212,6 +217,13 @@ export default function Machines() {
               }
             />
           ) : (
+            <>
+              {probing && (
+                <div className="flex items-center gap-2 px-4 pt-3 text-xs text-muted-foreground">
+                  <span className="inline-block h-2 w-2 bg-amber-400 rounded-full animate-pulse" />
+                  Checking machine status...
+                </div>
+              )}
             <Table>
               <TableHeader>
                 <TableRow>
@@ -290,6 +302,7 @@ export default function Machines() {
                 ))}
               </TableBody>
             </Table>
+            </>
           )}
         </div>
       </Card>