diff --git a/benchmarks/benchmark-fiat-crypto/Makefile b/benchmarks/benchmark-fiat-crypto/Makefile
index 794afd67f7..de4335fa82 100644
--- a/benchmarks/benchmark-fiat-crypto/Makefile
+++ b/benchmarks/benchmark-fiat-crypto/Makefile
@@ -11,8 +11,8 @@ bench:
 	@date -u +"%FT%TZ - $(NAME): done"
 
 perform: bedrock2_fiat_crypto.byte
-	/usr/bin/time -f "%E %R" $(COMPILER) --debug times --source-map $(EXTRA_ARGS) $< 2>&1 | \
-	ocaml -I +str str.cma ../utils/compilation_metrics.ml $(COMPILER) $(NAME) | \
+	/usr/bin/time -f "%E %R" $(COMPILER) --debug times --source-map $(EXTRA_ARGS) $< -o out.js 2>&1 | \
+	ocaml -I +str str.cma ../utils/compilation_metrics.ml $(COMPILER) $(NAME) out.js | \
 	sh ../utils/aggregate.sh $(KIND)
 
 bedrock2_fiat_crypto.byte: bedrock2_fiat_crypto.ml
diff --git a/benchmarks/benchmark-ocamlc/Makefile b/benchmarks/benchmark-ocamlc/Makefile
index 38471fa733..be6f814711 100644
--- a/benchmarks/benchmark-ocamlc/Makefile
+++ b/benchmarks/benchmark-ocamlc/Makefile
@@ -15,7 +15,7 @@ ARGS=ml/*.ml ml/*.ml ml/*.ml ml/*.ml ml/*.ml ml/*.ml ml/*.ml ml/*.ml
 
 perform:
 	/usr/bin/time -f "%E %R" $(COMPILER) --debug times --opt 2 --pretty `which ocamlc.byte` -o $(SCRIPT) 2>&1 | \
-	ocaml -I +str str.cma ../utils/compilation_metrics.ml $(COMPILER) $(NAME) | \
+	ocaml -I +str str.cma ../utils/compilation_metrics.ml $(COMPILER) $(NAME) $(SCRIPT) | \
 	sh ../utils/aggregate.sh $(KIND)
 	/usr/bin/time -f '{"compiler": "$(COMPILER)", "time":"%E"}' node $(SCRIPT) -c $(ARGS) 2>&1 | \
 	sh ../utils/format_metrics.sh exec | \
diff --git a/benchmarks/benchmark-partial-render-table/Makefile b/benchmarks/benchmark-partial-render-table/Makefile
index 353abcfd53..92889796d5 100644
--- a/benchmarks/benchmark-partial-render-table/Makefile
+++ b/benchmarks/benchmark-partial-render-table/Makefile
@@ -16,7 +16,7 @@ bench:
 perform:
 	/usr/bin/time -f "%E %R" $(COMPILER) --debug times --opt 2 --pretty main.bc-for-jsoo -o out.js 2>&1 | \
 	tee /dev/stderr | \
-	ocaml -I +str str.cma ../utils/compilation_metrics.ml $(COMPILER) "$(NAME)" | \
+	ocaml -I +str str.cma ../utils/compilation_metrics.ml $(COMPILER) "$(NAME)" out.js | \
 	sh ../utils/aggregate.sh $(KIND)
 	node $(SCRIPT) | \
 	tee /dev/stderr | \
diff --git a/benchmarks/utils/compilation_metrics.ml b/benchmarks/utils/compilation_metrics.ml
index ee002de5fa..8333a691d6 100644
--- a/benchmarks/utils/compilation_metrics.ml
+++ b/benchmarks/utils/compilation_metrics.ml
@@ -1,3 +1,9 @@
+let compiler = Sys.argv.(1)
+
+let benchmark_name = Sys.argv.(2)
+
+let output = Sys.argv.(3)
+
 let time_re = Str.regexp "^  \\([^ ].*\\): \\([0-9.]+\\)$"
 
 let () =
@@ -14,6 +20,21 @@ let () =
        last_line := l
      done
    with End_of_file -> ());
+  let file_size =
+    let file =
+      match compiler with
+      | "js_of_ocaml" -> output
+      | "wasm_of_ocaml" ->
+          let dir = Filename.chop_suffix output ".js" ^ ".assets" in
+          let contents = Sys.readdir dir in
+          let code =
+            Array.find_opt (fun nm -> Filename.check_suffix nm ".wasm") contents
+          in
+          Filename.concat dir (Option.get code)
+      | _ -> assert false
+    in
+    In_channel.(with_open_bin file length)
+  in
   let l = Hashtbl.fold (fun nm v rem -> (nm, v) :: rem) times [] in
   let l = List.filter (fun (_, v) -> v > 0.2) l in
   let l = List.map (fun (nm, v) -> "Compilation phases/" ^ nm, "s", v) l in
@@ -21,6 +42,7 @@ let () =
     Scanf.sscanf !last_line "%f:%f %f" (fun m s mem ->
         [ "Compilation time", "s", (m *. 60.) +. s
         ; "Compilation memory usage", "KiB", mem
+        ; "Code size", "KiB", float (Int64.to_int file_size / 1024)
         ])
   in
   Format.printf
@@ -28,8 +50,8 @@ let () =
   "results":
     [ { "name": "%s",
         "metrics":@.|}
-    (String.capitalize_ascii Sys.argv.(1))
-    Sys.argv.(2);
+    (String.capitalize_ascii compiler)
+    benchmark_name;
   Format.printf "          [ @[";
   List.iteri
     (fun i (nm, u, v) ->