diff --git a/.changes/fix-javascript-iife-esm-rewrite.md b/.changes/fix-javascript-iife-esm-rewrite.md
new file mode 100644
index 000000000..cfa0450ff
--- /dev/null
+++ b/.changes/fix-javascript-iife-esm-rewrite.md
@@ -0,0 +1,6 @@
+---
+"tauri": patch
+"tauri-codegen": patch
+---
+
+Detect ESM scripts and inject the invoke key directly instead of using an IIFE.
diff --git a/.changes/invoke-key-performance.md b/.changes/invoke-key-performance.md
new file mode 100644
index 000000000..6296fa582
--- /dev/null
+++ b/.changes/invoke-key-performance.md
@@ -0,0 +1,6 @@
+---
+"tauri": patch
+"tauri-codegen": patch
+---
+
+Improve invoke key code injection performance time rewriting code at compile time.
diff --git a/core/tauri-codegen/src/embedded_assets.rs b/core/tauri-codegen/src/embedded_assets.rs
index e87fbdebc..3316bbd5e 100644
--- a/core/tauri-codegen/src/embedded_assets.rs
+++ b/core/tauri-codegen/src/embedded_assets.rs
@@ -177,6 +177,38 @@ impl EmbeddedAssets {
           .to_vec();
       }
     }
+    let is_javascript = ["js", "cjs", "mjs"]
+      .iter()
+      .any(|e| path.extension() == Some(OsStr::new(e)));
+    if is_javascript {
+      let js = String::from_utf8_lossy(&input).into_owned();
+      input = if [
+        "import{", "import*", "import ", "export{", "export*", "export ",
+      ]
+      .iter()
+      .any(|t| js.contains(t))
+      {
+        format!(
+          r#"
+            const __TAURI_INVOKE_KEY__ = __TAURI__INVOKE_KEY_TOKEN__;
+            {}
+          "#,
+          js
+        )
+        .as_bytes()
+        .to_vec()
+      } else {
+        format!(
+          r#"(function () {{
+            const __TAURI_INVOKE_KEY__ = __TAURI__INVOKE_KEY_TOKEN__;
+            {}
+          }})()"#,
+          js
+        )
+        .as_bytes()
+        .to_vec()
+      };
+    }
 
     // we must canonicalize the base of our paths to allow long paths on windows
     let out_dir = std::env::var("OUT_DIR")
diff --git a/core/tauri/src/manager.rs b/core/tauri/src/manager.rs
index 001cedd10..b61982561 100644
--- a/core/tauri/src/manager.rs
+++ b/core/tauri/src/manager.rs
@@ -467,13 +467,10 @@ impl<P: Params> WindowManager<P> {
             if is_javascript {
               let js = String::from_utf8_lossy(&asset).into_owned();
               Ok(
-                format!(
-                  r#"(function () {{
-                    const __TAURI_INVOKE_KEY__ = {};
-                    {}
-                  }})()"#,
-                  manager.generate_invoke_key(),
-                  js
+                js.replacen(
+                  "__TAURI__INVOKE_KEY_TOKEN__",
+                  &manager.generate_invoke_key().to_string(),
+                  1,
                 )
                 .as_bytes()
                 .to_vec(),