diff --git a/bench_test.go b/bench_test.go
new file mode 100644
index 0000000..db93bff
--- /dev/null
+++ b/bench_test.go
@@ -0,0 +1,49 @@
+package it_test
+
+import (
+	"testing"
+
+	"github.com/gomoni/it"
+)
+
+var in1M []int
+
+func init() {
+	in1M = make([]int, 1024*1024)
+	for idx := range in1M {
+		in1M[idx] = idx
+	}
+}
+
+func rangeFilter(in []int, filterFunc it.FilterFunc[int]) []int {
+	ret := make([]int, 0, len(in))
+	for _, i := range in {
+		if filterFunc(i) {
+			ret = append(ret, i)
+		}
+	}
+	return ret
+}
+
+func BenchmarkRangeFilter(b *testing.B) {
+	for range b.N {
+		rangeFilter(in1M, func(i int) bool { return i%2 == 0 })
+	}
+}
+
+func BenchmarkItFilterSlice(b *testing.B) {
+	for range b.N {
+		seq0 := it.Filter(it.FromSlice(in1M), func(i int) bool { return i%2 == 0 })
+		it.AsSlice(seq0)
+	}
+}
+
+func BenchmarkItFilterFor(b *testing.B) {
+	for range b.N {
+		seq0 := it.Filter(it.FromSlice(in1M), func(i int) bool { return i%2 == 0 })
+		cnt := 0
+		for value := range seq0 {
+			cnt += value
+		}
+	}
+}