diff --git a/Cargo.toml b/Cargo.toml
index 198df76..c59bb3e 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -12,7 +12,7 @@ crate-type=["cdylib"]
 [profile.release]
 debug = false
 codegen-units = 1
-opt-level = "s" #optimize for size
+opt-level = "z" #optimize for size
 lto = true
 strip = true
 
diff --git a/build.sh b/build.sh
index 762040d..a8cbf48 100755
--- a/build.sh
+++ b/build.sh
@@ -1,18 +1,20 @@
 #!/bin/bash
 set -e
 
-rm -fr tmp pkg | true #delete tmp folder if exists
+rm -fr tmp | true
+rm -fr pkg | true
 
 #apply optimizations via wasm-opt
 wasm_opt() {
-    wasm-opt -Os -o pkg/integral_site_bg_2.wasm pkg/integral_site_bg.wasm
+    wasm-opt -Oz -o pkg/integral_site_bg_2.wasm pkg/integral_site_bg.wasm
     mv pkg/integral_site_bg_2.wasm pkg/integral_site_bg.wasm
 }
 
 if test "$1" == "" || test "$1" == "release"; then
     wasm-pack build --target web --release --no-typescript
+    echo "Binary size (pre-wasm_opt): $(du -sb pkg/integral_site_bg.wasm)"
     wasm_opt #apply wasm optimizations
-
+    echo "Binary size (pre-strip): $(du -sb pkg/integral_site_bg.wasm)"
     llvm-strip --strip-all pkg/integral_site_bg.wasm
 elif test "$1" == "debug"; then
     wasm-pack build --target web --debug --no-typescript
diff --git a/src/function.rs b/src/function.rs
index 654a8af..6e048fb 100644
--- a/src/function.rs
+++ b/src/function.rs
@@ -38,6 +38,7 @@ pub struct Function {
     sum: RiemannSum,
 }
 
+// x^2 function, set here so we don't have to regenerate it every time a new function is made
 fn default_function(x: f64) -> f64 { x.powi(2) }
 
 impl Function {