diff --git a/bin/ecs.mjs b/bin/ecs.mjs
index b8ddf67..eb8debc 100755
--- a/bin/ecs.mjs
+++ b/bin/ecs.mjs
@@ -1,6 +1,6 @@
 import { join, relative } from "node:path"
 import { existsSync } from "node:fs"
-import { readdir, readFile, writeFile } from "node:fs/promises"
+import { readdir, readFile, rm, unlink, writeFile } from "node:fs/promises"
 import { Script } from "node:vm"
 import { Parcel } from "@parcel/core"
 import { fileURLToPath } from "node:url"
@@ -33,6 +33,17 @@ async function main(args) {
 async function build() {
     const config = await getConfig()
 
+    // clean dist
+    if (existsSync(config.dist)) {
+        for (const file of await readdir(config.dist, { withFileTypes: true })) {
+            if (file.isDirectory()) {
+                await rm(join(config.dist, file.name), { recursive: true })
+            } else {
+                await unlink(join(config.dist, file.name))
+            }
+        }
+    }
+
     let bundler = new Parcel({
         entries: config.htmlFiles.map((file) => join(config.src, file)),
         config: "@parcel/config-default",
diff --git a/lib/builtin/systems/html.ts b/lib/builtin/systems/html.ts
index 6634b7a..9e3ec9c 100644
--- a/lib/builtin/systems/html.ts
+++ b/lib/builtin/systems/html.ts
@@ -112,29 +112,10 @@ export function renderHtmlRoot(): void {
         render(e, el)
     }
 
-    diffRender(root.element, el, false)
+    diffRender(root.element, el)
 }
 
-function diffRender(old: Element, next: HTMLElement, deleteAttributes = true): void {
-    // check attributes
-    const oldAttrs = old.attributes
-    const nextAttrs = next.attributes
-    for (let i = 0; i < nextAttrs.length; i++) {
-        const nextAttr = nextAttrs[i]!
-        const oldAttr = oldAttrs.getNamedItem(nextAttr.name)
-        if (!oldAttr || oldAttr.value !== nextAttr.value) {
-            old.setAttribute(nextAttr.name, nextAttr.value)
-        }
-    }
-    if (deleteAttributes) {
-        for (let i = 0; i < oldAttrs.length; i++) {
-            const oldAttr = oldAttrs[i]!
-            if (nextAttrs.getNamedItem(oldAttr.name) === null) {
-                old.removeAttribute(oldAttr.name)
-            }
-        }
-    }
-
+function diffRender(old: Element, next: HTMLElement) {
     if (old.childNodes.length !== next.childNodes.length) {
         old.innerHTML = next.innerHTML
         return