diff --git a/CMakeLists.txt b/CMakeLists.txt
index caeef5f..1182bb3 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -41,6 +41,7 @@ add_executable(donar ${CSOURCES} src/donar.c)
 add_executable(measlat ${CSOURCES} src/meas_lat.c)
 add_executable(udpecho ${CSOURCES} src/udp_echo.c)
 add_executable(torecho ${CSOURCES} src/tor_echo.c)
+add_executable(capdiff ${CSOURCES} src/capdiff.c)
 
 find_package(PkgConfig REQUIRED)
 pkg_search_module(GLIB REQUIRED glib-2.0)
@@ -57,6 +58,9 @@ target_link_libraries(udpecho ${GLIB_LDFLAGS})
 target_include_directories(torecho PRIVATE ${GLIB_INCLUDE_DIRS})
 target_link_libraries(torecho ${GLIB_LDFLAGS})
 
-install(TARGETS donar measlat udpecho torecho
+target_include_directories(capdiff PRIVATE ${GLIB_INCLUDE_DIRS})
+target_link_libraries(capdiff ${GLIB_LDFLAGS})
+
+install(TARGETS donar measlat udpecho torecho capdiff
         RUNTIME DESTINATION bin
         LIBRARY DESTINATION lib)
diff --git a/src/capdiff.c b/src/capdiff.c
new file mode 100644
index 0000000..0912c23
--- /dev/null
+++ b/src/capdiff.c
@@ -0,0 +1,87 @@
+#include <stdlib.h>
+#include <stdio.h>
+#include "packet.h"
+
+int main(int argc, char** argv) {
+  if (argc != 3) {
+    fprintf(stderr, "Usage %s ./cap.0 ./cap.1\n", argv[0]);
+    exit(EXIT_FAILURE);
+  }
+  uint8_t verbose = 0;
+
+  FILE *fd[2]; size_t sz[2];
+  for (int i = 0; i < 2; i++) {
+    if ((fd[i] = fopen(argv[i+1], "r")) == NULL) {
+      perror("Unable to open file");
+      exit(EXIT_FAILURE);
+    }
+
+    fseek(fd[i], 0, SEEK_END);
+    sz[i] = ftell(fd[i]);
+    fseek(fd[i], 0, SEEK_SET);
+  }
+
+  if (sz[0] != sz[1]) {
+    printf("[!!] %s has %ld entries, %s has %ld entries\n",
+           argv[1],
+           sz[0]/sizeof(struct buffer_packet),
+           argv[2],
+           sz[1]/sizeof(struct buffer_packet));
+  } else if (verbose) {
+    printf("[OK] %s and %s have %ld entries\n",
+           argv[1],
+           argv[2],
+           sz[0]/sizeof(struct buffer_packet));
+  }
+
+  size_t to_read = sz[0] < sz[1] ? sz[0] : sz[1];
+  size_t to_read_obj = to_read / sizeof(struct buffer_packet);
+  uint16_t expected_id = 0;
+  struct buffer_packet bpread[2];
+  for (size_t c = 0; c < to_read_obj; c++) {
+    for (int i = 0; i < 2; i++) fread(&bpread[i], sizeof(struct buffer_packet), 1, fd[i]);
+    /*if (expected_id != bpread[0].ip.ap.fmt.content.clear.id || expected_id != bpread[1].ip.ap.fmt.content.clear.id) {
+      printf("[!!] expected id is %d, %s has id %d, %s has id %d\n",
+             expected_id,
+             argv[1],
+             bpread[0].ip.ap.fmt.content.clear.id,
+             argv[2],
+             bpread[1].ip.ap.fmt.content.clear.id);
+    }*/
+
+    uint8_t is_same_size = bpread[0].ip.ap.fmt.headers.size == bpread[1].ip.ap.fmt.headers.size;
+    if (!is_same_size) {
+      printf("[!!] %s packet has size %d, %s packet has size %d for expected id %d\n",
+             argv[1],
+             bpread[0].ip.ap.fmt.headers.size,
+             argv[2],
+             bpread[1].ip.ap.fmt.headers.size,
+             expected_id);
+    } else if (verbose) {
+      printf("[OK] %s and %s packets for expected id %d have size %d\n",
+             argv[1],
+             argv[2],
+             expected_id,
+             bpread[0].ip.ap.fmt.headers.size);
+    }
+
+    size_t s1 = bpread[0].ip.ap.fmt.headers.size, s2 = bpread[1].ip.ap.fmt.headers.size;
+    size_t max_size = s1 > s2 ? s1 : s2;
+    for (size_t idx = 0; idx < max_size; idx++) {
+      char e1 = (&bpread[0].ip.ap.raw)[idx], e2 = (&bpread[0].ip.ap.raw)[idx];
+      if (e1 != e2) {
+        printf("[!!] for expected id %d, byte 0x%04x is different: 0x%02x vs 0x%02x\n", expected_id, (uint16_t)idx, (uint8_t)e1, (uint8_t)e2);
+      }
+    }
+
+    expected_id++;
+  }
+
+
+  for (int i = 0; i < 2; i++) {
+    fclose(fd[i]);
+  }
+
+  printf("done\n");
+  return 0;
+}