diff --git a/scripts/build_demo_web.sh b/scripts/build_demo_web.sh
index 658c6bb3ca5..e905066d42a 100755
--- a/scripts/build_demo_web.sh
+++ b/scripts/build_demo_web.sh
@@ -19,23 +19,37 @@ OPTIMIZE=false
 BUILD=debug
 BUILD_FLAGS=""
 WEB_GPU=false
+WASM_OPT_FLAGS="-O2 --fast-math"
 
 while test $# -gt 0; do
   case "$1" in
     -h|--help)
       echo "build_demo_web.sh [--release] [--webgpu] [--open]"
       echo ""
-      echo "  --release: Build with --release, and enable extra optimization step"
-      echo "             Runs wasm-opt."
-      echo "             NOTE: --release also removes debug symbols which are otherwise useful for in-browser profiling."
+      echo "  -g:        Keep debug symbols even with --release."
+      echo "             These are useful profiling and size trimming."
       echo ""
-      echo "  --webgpu:  Build a binary for WebGPU instead of WebGL"
-      echo "             Note that the resulting wasm will ONLY work on browsers with WebGPU."
+      echo "  --open:    Open the result in a browser."
+      echo ""
+      echo "  --release: Build with --release, and then run wasm-opt."
+      echo "             NOTE: --release also removes debug symbols, unless you also use -g."
       echo ""
-      echo "  --open:    Open the result in a browser"
+      echo "  --webgpu:  Build a binary for WebGPU instead of WebGL."
+      echo "             Note that the resulting wasm will ONLY work on browsers with WebGPU."
       exit 0
       ;;
 
+    -g)
+      shift
+      WASM_OPT_FLAGS="${WASM_OPT_FLAGS} -g"
+      echo "'${WASM_OPT_FLAGS}'"
+      ;;
+
+    --open)
+      shift
+      OPEN=true
+      ;;
+
     --release)
       shift
       OPTIMIZE=true
@@ -48,11 +62,6 @@ while test $# -gt 0; do
       WEB_GPU=true
       ;;
 
-    --open)
-      shift
-      OPEN=true
-      ;;
-
     *)
       echo "Unknown option: $1"
       exit 1
@@ -96,6 +105,7 @@ wasm-bindgen "${WASM_PATH}" --out-dir web_demo --out-name ${OUT_FILE_NAME} --no-
 # if this fails with "error: cannot import from modules (`env`) with `--no-modules`", you can use:
 # wasm2wat target/wasm32-unknown-unknown/release/egui_demo_app.wasm | rg env
 # wasm2wat target/wasm32-unknown-unknown/release/egui_demo_app.wasm | rg "call .now\b" -B 20 # What calls `$now` (often a culprit)
+# Or use https://rustwasm.github.io/twiggy/usage/command-line-interface/paths.html#twiggy-paths
 
 # to get wasm-strip:  apt/brew/dnf install wabt
 # wasm-strip ${FINAL_WASM_PATH}
@@ -103,7 +113,7 @@ wasm-bindgen "${WASM_PATH}" --out-dir web_demo --out-name ${OUT_FILE_NAME} --no-
 if [[ "${OPTIMIZE}" = true ]]; then
   echo "Optimizing wasm…"
   # to get wasm-opt:  apt/brew/dnf install binaryen
-  wasm-opt "${FINAL_WASM_PATH}" -O2 --fast-math -o "${FINAL_WASM_PATH}" # add -g to get debug symbols
+  wasm-opt "${FINAL_WASM_PATH}" $WASM_OPT_FLAGS -o "${FINAL_WASM_PATH}"
 fi
 
 echo "Finished ${FINAL_WASM_PATH}"