diff --git a/DOCS/man/javascript.rst b/DOCS/man/javascript.rst
index db12b65a09..75db7cd99e 100644
--- a/DOCS/man/javascript.rst
+++ b/DOCS/man/javascript.rst
@@ -153,6 +153,10 @@ success, ``fn`` is called always a-sync, ``error`` is empty string on success.
 
 ``mp.unregister_script_message(name)``
 
+``mp.create_osd_overlay(format)``
+
+``mp.get_osd_size()``  (returned object has properties: width, height, aspect)
+
 ``mp.msg.log(level, ...)``
 
 ``mp.msg.fatal(...)``
diff --git a/player/javascript.c b/player/javascript.c
index 5981eb848d..fa3b09c7f3 100644
--- a/player/javascript.c
+++ b/player/javascript.c
@@ -732,17 +732,6 @@ static void script_get_time_ms(js_State *J)
     js_pushnumber(J, mpv_get_time_us(jclient(J)) / (double)(1000));
 }
 
-static void script_set_osd_ass(js_State *J)
-{
-    struct script_ctx *ctx = jctx(J);
-    int res_x = jsL_checkint(J, 1);
-    int res_y = jsL_checkint(J, 2);
-    const char *text = js_tostring(J, 3);
-    //osd_set_external(ctx->mpctx->osd, ctx->client, res_x, res_y, (char *)text);
-    mp_wakeup_core(ctx->mpctx);
-    push_success(J);
-}
-
 // push object with properties names (NULL terminated) with respective vals
 static void push_nums_obj(js_State *J, const char * const names[],
                           const double vals[])
@@ -754,16 +743,6 @@ static void push_nums_obj(js_State *J, const char * const names[],
     }
 }
 
-// args: none, return: object with properties width, height, aspect
-static void script_get_osd_size(js_State *J)
-{
-    struct mp_osd_res r = osd_get_vo_res(jctx(J)->mpctx->osd);
-    double ar = 1.0 * r.w / MPMAX(r.h, 1) / (r.display_par ? r.display_par : 1);
-    const char * const names[] = {"width", "height", "aspect", NULL};
-    const double vals[] = {r.w, r.h, ar};
-    push_nums_obj(J, names, vals);
-}
-
 // args: none, return: object with properties top, bottom, left, right
 static void script_get_osd_margins(js_State *J)
 {
@@ -1258,8 +1237,6 @@ static const struct fn_entry main_fns[] = {
     FN_ENTRY(get_wakeup_pipe, 0),
     FN_ENTRY(_hook_add, 3),
     FN_ENTRY(_hook_continue, 1),
-    FN_ENTRY(set_osd_ass, 3),
-    FN_ENTRY(get_osd_size, 0),
     FN_ENTRY(get_osd_margins, 0),
     FN_ENTRY(get_mouse_pos, 0),
     FN_ENTRY(input_set_section_mouse_area, 5),
diff --git a/player/javascript/defaults.js b/player/javascript/defaults.js
index 2ae3fe74d0..18edab35b7 100644
--- a/player/javascript/defaults.js
+++ b/player/javascript/defaults.js
@@ -192,6 +192,59 @@ mp.utils.shared_script_property_set = shared_script_property_set;
 mp.utils.shared_script_property_get = shared_script_property_get;
 mp.utils.shared_script_property_observe = shared_script_property_observe;
 
+// osd-ass
+var next_assid = 1;
+mp.create_osd_overlay = function create_osd_overlay(format) {
+    return {
+        format: format || "ass-events",
+        id: next_assid++,
+        data: "",
+        res_x: 0,
+        res_y: 720,
+        z: 0,
+
+        update: function ass_update() {
+            mp.command_native({
+                name: "osd-overlay",
+                format: this.format,
+                id: this.id,
+                data: this.data,
+                res_x: Math.round(this.res_x),
+                res_y: Math.round(this.res_y),
+                z: this.z,
+            });
+            return mp.last_error() ? undefined : true;
+        },
+
+        remove: function ass_remove() {
+            mp.command_native({
+                name: "osd-overlay",
+                id: this.id,
+                format: "none",
+                data: "",
+            });
+            return mp.last_error() ? undefined : true;
+        },
+    };
+}
+
+// osd-ass legacy API
+mp.set_osd_ass = function set_osd_ass(res_x, res_y, data) {
+    if (!mp._legacy_overlay)
+        mp._legacy_overlay = mp.create_osd_overlay("ass-events");
+    mp._legacy_overlay.res_x = res_x;
+    mp._legacy_overlay.res_y = res_y;
+    mp._legacy_overlay.data = data;
+    return mp._legacy_overlay.update();
+}
+
+mp.get_osd_size = function get_osd_size() {
+    var w = mp.get_property_number("osd-width", 0),
+        h = mp.get_property_number("osd-height", 0),
+        par = mp.get_property_number("osd-par", 0);
+    return {width: w, height: h, aspect: w / (h || 1) / (par || 1)};
+}
+
 /**********************************************************************
  *  key bindings
  *********************************************************************/