diff --git a/libr/anal/sign.c b/libr/anal/sign.c
index f100a4094d..c4ffa4e94b 100644
--- a/libr/anal/sign.c
+++ b/libr/anal/sign.c
@@ -162,7 +162,7 @@ R_API bool r_sign_deserialize(RAnal *a, RSignItem *it, const char *k, const char
 		token = word + 2;
 		if (!strcmp (word, "*")) {
 			continue;
-		} 
+		}
 		if (strlen (word) < 3 || word[1] != ':') {
 			eprintf ("Corrupted zignatures database (%s)\n", word);
 			break;
@@ -837,6 +837,229 @@ R_API bool r_sign_delete(RAnal *a, const char *name) {
 	return sdb_remove (a->sdb_zigns, k, 0);
 }
 
+static bool matchBytes(RSignItem *a, RSignItem *b) {
+	if (a->bytes && b->bytes) {
+		if (a->bytes->size == b->bytes->size) {
+			return !memcmp (a->bytes->bytes, b->bytes->bytes, b->bytes->size);
+		}
+	}
+	return false;
+}
+
+static bool matchGraph(RSignItem *a, RSignItem *b) {
+	if (a->graph && b->graph) {
+		if (a->graph->cc != b->graph->cc) {
+			return false;
+		}
+		if (a->graph->nbbs != b->graph->nbbs) {
+			return false;
+		}
+		if (a->graph->ebbs != b->graph->ebbs) {
+			return false;
+		}
+		if (a->graph->edges != b->graph->edges) {
+			return false;
+		}
+		if (a->graph->bbsum!= b->graph->bbsum) {
+			return false;
+		}
+		return true;
+	}
+	return false;
+}
+
+R_API bool r_sign_diff(RAnal *a, const char *other_space_name) {
+	char k[R_SIGN_KEY_MAXSZ];
+
+	r_return_val_if_fail (a && other_space_name, false);
+
+	RSpace *current_space = r_spaces_current (&a->zign_spaces);
+	if (!current_space) {
+		return false;
+	}
+	RSpace *other_space = r_spaces_get (&a->zign_spaces, other_space_name);
+	if (!other_space) {
+		return false;
+	}
+
+	serializeKey (a, current_space, "", k);
+	SdbList *current_zigns = sdb_foreach_match (a->sdb_zigns, k, false);
+
+	serializeKey (a, other_space, "", k);
+	SdbList *other_zigns = sdb_foreach_match (a->sdb_zigns, k, false);
+
+	eprintf ("Diff %d %d\n", (int)ls_length (current_zigns), (int)ls_length (other_zigns));
+
+	SdbListIter *iter;
+	SdbKv *kv;
+	RList *lb = NULL;
+	RList *la = r_list_new ();
+	if (!la) {
+		goto beach;
+	}
+	ls_foreach (current_zigns, iter, kv) {
+		RSignItem *it = r_sign_item_new ();
+		if (!it) {
+			goto beach;
+		}
+		if (r_sign_deserialize (a, it, kv->base.key, kv->base.value)) {
+			r_list_append (la, it);
+		} else {
+			r_sign_item_free (it);
+		}
+	}
+	lb = r_list_new ();
+	if (!lb) {
+		goto beach;
+	}
+	ls_foreach (other_zigns, iter, kv) {
+		RSignItem *it = r_sign_item_new ();
+		if (!it) {
+			goto beach;
+		}
+		if (r_sign_deserialize (a, it, kv->base.key, kv->base.value)) {
+			r_list_append (lb, it);
+		} else {
+			r_sign_item_free (it);
+		}
+	}
+
+	ls_free (current_zigns);
+	ls_free (other_zigns);
+
+	RListIter *itr;
+	RListIter *itr2;
+	RSignItem *si;
+	RSignItem *si2;
+
+	// do the sign diff here
+	r_list_foreach (la, itr, si) {
+		if (strstr (si->name, "imp.")) {
+			continue;
+		}
+		r_list_foreach (lb, itr2, si2) {
+			if (strstr (si2->name, "imp.")) {
+				continue;
+			}
+			if (matchBytes (si, si2)) {
+				a->cb_printf ("0x%08"PFMT64x" 0x%08"PFMT64x" B %s\n", si->addr, si2->addr, si->name);
+			}
+			if (matchGraph (si, si2)) {
+				a->cb_printf ("0x%08"PFMT64x" 0x%08"PFMT64x" G %s\n", si->addr, si2->addr, si->name);
+			}
+		}
+	}
+
+	r_list_free (la);
+	r_list_free (lb);
+
+	return true;
+beach:
+	ls_free (current_zigns);
+	ls_free (other_zigns);
+	r_list_free (la);
+	r_list_free (lb);
+
+	return false;
+}
+
+R_API bool r_sign_diff_by_name(RAnal *a, const char *other_space_name, bool not_matching) {
+	char k[R_SIGN_KEY_MAXSZ];
+
+	r_return_val_if_fail (a && other_space_name, false);
+
+	RSpace *current_space = r_spaces_current (&a->zign_spaces);
+	if (!current_space) {
+		return false;
+	}
+	RSpace *other_space = r_spaces_get (&a->zign_spaces, other_space_name);
+	if (!other_space) {
+		return false;
+	}
+
+	serializeKey (a, current_space, "", k);
+	SdbList *current_zigns = sdb_foreach_match (a->sdb_zigns, k, false);
+
+	serializeKey (a, other_space, "", k);
+	SdbList *other_zigns = sdb_foreach_match (a->sdb_zigns, k, false);
+
+	eprintf ("Diff by name %d %d (%s)\n", (int)ls_length (current_zigns), (int)ls_length (other_zigns), not_matching ? "not maching" : "matching");
+
+	SdbListIter *iter;
+	SdbKv *kv;
+	RList *lb = NULL;
+	RList *la = r_list_new ();
+	if (!la) {
+		goto beach;
+	}
+	ls_foreach (current_zigns, iter, kv) {
+		RSignItem *it = r_sign_item_new ();
+		if (!it) {
+			goto beach;
+		}
+		if (r_sign_deserialize (a, it, kv->base.key, kv->base.value)) {
+			r_list_append (la, it);
+		} else {
+			r_sign_item_free (it);
+		}
+	}
+	lb = r_list_new ();
+	if (!la) {
+		goto beach;
+	}
+	ls_foreach (other_zigns, iter, kv) {
+		RSignItem *it = r_sign_item_new ();
+		if (!it) {
+			goto beach;
+		}
+		if (r_sign_deserialize (a, it, kv->base.key, kv->base.value)) {
+			r_list_append (lb, it);
+		} else {
+			r_sign_item_free (it);
+		}
+	}
+
+	ls_free (current_zigns);
+	ls_free (other_zigns);
+
+	RListIter *itr;
+	RListIter *itr2;
+	RSignItem *si;
+	RSignItem *si2;
+	size_t current_space_name_len = strlen (current_space->name);
+	size_t other_space_name_len = strlen (other_space->name);
+
+	r_list_foreach (la, itr, si) {
+		if (strstr (si->name, "imp.")) {
+			continue;
+		}
+		r_list_foreach (lb, itr2, si2) {
+			if (strcmp (si->name + current_space_name_len + 1, si2->name + other_space_name_len + 1)) {
+				continue;
+			}
+			bool bytesMatch = matchBytes (si, si2);
+			bool graphMatch = matchGraph (si, si2);
+			if ((bytesMatch && !not_matching) || (!bytesMatch && not_matching)) {
+				a->cb_printf ("0x%08"PFMT64x" 0x%08"PFMT64x" B %s\n", si->addr, si2->addr, si->name);
+			}
+			if ((graphMatch && !not_matching) || (!graphMatch && not_matching)) {
+				a->cb_printf ("0x%08"PFMT64x" 0x%08"PFMT64x" G %s\n", si->addr, si2->addr, si->name);
+			}
+		}
+	}
+
+	r_list_free (la);
+	r_list_free (lb);
+
+	return true;
+beach:
+	ls_free (current_zigns);
+	ls_free (other_zigns);
+	r_list_free (la);
+	r_list_free (lb);
+
+	return false;
+}
 struct ctxListCB {
 	RAnal *anal;
 	int idx;
diff --git a/libr/core/cmd_zign.c b/libr/core/cmd_zign.c
index 6797ac2dc9..31ee5773b2 100644
--- a/libr/core/cmd_zign.c
+++ b/libr/core/cmd_zign.c
@@ -22,7 +22,7 @@ static const char *help_msg_z[] = {
 	"zo", "[?]", "manage zignature files",
 	"zf", "[?]", "manage FLIRT signatures",
 	"z/", "[?]", "search zignatures",
-	"zc", " [zspace]", "compare current zignspace zignatures with others",
+	"zc", "[?]", "compare current zignspace zignatures with another one",
 	"zs", "[?]", "manage zignspaces",
 	"zi", "", "show zignatures matching information",
 	NULL
@@ -74,6 +74,14 @@ static const char *help_msg_zs[] = {
 	NULL
 };
 
+static const char *help_msg_zc[] = {
+	"Usage:", "zc[n!] other_space ", "# Compare zignspaces",
+	"zc", " other_space", "compare all current space with other_space",
+	"zcn", " other_space", "compare current space with zigns with same name on other_space",
+	"zcn!", " other_space", "same as above but show the ones not matching",
+	NULL
+};
+
 static void cmd_zign_init(RCore *core) {
 	DEFINE_CMD_DESCRIPTOR (core, z);
 	DEFINE_CMD_DESCRIPTOR_SPECIAL (core, z/, z_slash);
@@ -81,6 +89,7 @@ static void cmd_zign_init(RCore *core) {
 	DEFINE_CMD_DESCRIPTOR (core, zf);
 	DEFINE_CMD_DESCRIPTOR (core, zo);
 	DEFINE_CMD_DESCRIPTOR (core, zs);
+	DEFINE_CMD_DESCRIPTOR (core, zc);
 }
 
 static bool addFcnHash(RCore *core, RAnalFunction *fcn, const char *name) {
@@ -158,7 +167,7 @@ static char *getFcnComments(RCore *core, RAnalFunction *fcn) {
 	if (r && *r) {
 		return r;
 	}
-	// 
+	//
 	return NULL;
 }
 #endif
@@ -820,8 +829,46 @@ TODO: add useXRefs, useName
 }
 
 static int cmdCompare(void *data, const char *input) {
-	eprintf ("TODO\n");
-	return 0;
+	RCore *core = (RCore *) data;
+
+	switch (*input) {
+	case ' ':
+		if (!input[1]) {
+			eprintf ("usage: zc other_space\n");
+			return false;
+		}
+		return r_sign_diff (core->anal, input + 1);
+		break;
+	case 'n':
+		switch (input[1]) {
+		case ' ':
+			if (!input[2]) {
+				eprintf ("usage: zcn other_space\n");
+				return false;
+			}
+			return r_sign_diff_by_name (core->anal, input + 2, false);
+			break;
+		case '!':
+			if (input[2] != ' ' || !input[3]) {
+				eprintf ("usage: zcn! other_space\n");
+				return false;
+			}
+			return r_sign_diff_by_name (core->anal, input + 3, true);
+			break;
+		default:
+			eprintf ("usage: zcn! other_space\n");
+			return false;
+		}
+		break;
+	case '?':
+		r_core_cmd_help (core, help_msg_zc);
+		break;
+	default:
+		eprintf ("usage: zc[?n!] other_space\n");
+		return false;
+	}
+
+	return true;
 }
 
 static int cmdCheck(void *data, const char *input) {
diff --git a/libr/include/r_sign.h b/libr/include/r_sign.h
index 8d033089ec..272493b197 100644
--- a/libr/include/r_sign.h
+++ b/libr/include/r_sign.h
@@ -126,6 +126,9 @@ R_API RList *r_sign_fcn_vars(RAnal *a, RAnalFunction *fcn);
 R_API int r_sign_is_flirt(RBuffer *buf);
 R_API void r_sign_flirt_dump(const RAnal *anal, const char *flirt_file);
 R_API void r_sign_flirt_scan(RAnal *anal, const char *flirt_file);
+
+R_API bool r_sign_diff(RAnal *a, const char *other_space_name);
+R_API bool r_sign_diff_by_name(RAnal *a, const char *other_space_name, bool not_matching);
 #endif
 
 #ifdef __cplusplus