diff --git a/2024/src/aoc/days/day25.py b/2024/src/aoc/days/day25.py
new file mode 100644
index 0000000..a500a3e
--- /dev/null
+++ b/2024/src/aoc/days/day25.py
@@ -0,0 +1,30 @@
+import numpy
+
+from . import CombinedRunner
+
+
+class DayRunner(CombinedRunner):
+    @classmethod
+    def run_both(cls, input: str) -> tuple[int, None]:
+        blocks = input.strip().split("\n\n")
+
+        keys = []
+        locks = []
+
+        for block in blocks:
+            grid = numpy.array(list(map(list, block.splitlines())))
+            heights = numpy.count_nonzero(grid == "#", axis=0)
+
+            if block.startswith("#####"):
+                locks.append(heights)
+            else:
+                keys.append(heights)
+
+        fitting = 0
+
+        for key in keys:
+            for lock in locks:
+                if numpy.all((key + lock) <= 7):
+                    fitting += 1
+
+        return fitting, None
diff --git a/2024/tests/samples/25.txt b/2024/tests/samples/25.txt
new file mode 100644
index 0000000..8e29855
--- /dev/null
+++ b/2024/tests/samples/25.txt
@@ -0,0 +1,39 @@
+#####
+.####
+.####
+.####
+.#.#.
+.#...
+.....
+
+#####
+##.##
+.#.##
+...##
+...#.
+...#.
+.....
+
+.....
+#....
+#....
+#...#
+#.#.#
+#.###
+#####
+
+.....
+.....
+#.#..
+###..
+###.#
+###.#
+#####
+
+.....
+.....
+.....
+#....
+#.#..
+#.#.#
+#####
diff --git a/2024/tests/test_day25.py b/2024/tests/test_day25.py
new file mode 100644
index 0000000..838d135
--- /dev/null
+++ b/2024/tests/test_day25.py
@@ -0,0 +1,7 @@
+from aoc.days.day25 import DayRunner
+
+from . import get_data
+
+
+def test_sample_part1() -> None:
+    assert DayRunner.part1(get_data(25)) == 3