diff --git a/depell/src/index.js b/depell/src/index.js
index 040c30d..8b4fee3 100644
--- a/depell/src/index.js
+++ b/depell/src/index.js
@@ -44,8 +44,8 @@ async function getFmtInstance() {
 	return fmtInstance ??= (await fmtInstaceFuture).instance;
 }
 
-/** @param {WebAssembly.Instance} instance @param {string} code @param {"fmt" | "minify"} action
- * @returns {string | undefined} */
+/** @param {WebAssembly.Instance} instance @param {string} code @param {"tok" | "fmt" | "minify"} action
+ * @returns {string | Uint8Array | undefined} */
 function modifyCode(instance, code, action) {
 	let {
 		INPUT, INPUT_LEN,
@@ -54,6 +54,7 @@ function modifyCode(instance, code, action) {
 	} = instance.exports;
 
 	let funs = { fmt, tok, minify };
+	let fun = funs[action];
 	if (!(true
 		&& memory instanceof WebAssembly.Memory
 		&& INPUT instanceof WebAssembly.Global
@@ -61,9 +62,8 @@ function modifyCode(instance, code, action) {
 		&& OUTPUT instanceof WebAssembly.Global
 		&& OUTPUT_LEN instanceof WebAssembly.Global
 		&& funs.hasOwnProperty(action)
-		&& typeof funs[action] === "function"
+		&& typeof fun === "function"
 	)) never();
-	let fun = funs[action];
 
 	if (action !== "fmt") {
 		INPUT = OUTPUT;
@@ -133,7 +133,7 @@ function packPosts(posts, view) {
  * @return {Uint8Array} */
 function bufSlice(mem, ptr, len) {
 	return new Uint8Array(mem.buffer, ptr.value,
-			new DataView(mem.buffer).getUint32(len.value, true));
+		new DataView(mem.buffer).getUint32(len.value, true));
 }
 
 /** @param {WebAssembly.Memory} mem
@@ -283,27 +283,27 @@ async function bindCodeEdit(target) {
 }
 
 /**
- * @type {{ Array<string> }}
+ * @type {Array<string>}
  * to be synched with `enum TokenGroup` in bytecode/src/fmt.rs */
 const TOK_CLASSES = [
-    'Blank',
-    'Comment',
-    'Keyword',
-    'Identifier',
-    'Directive',
-    'Number',
-    'String',
-    'Op',
-    'Assign',
-    'Paren',
-    'Bracket',
-    'Colon',
-    'Comma',
-    'Dot',
-    'Ctor',
+	'Blank',
+	'Comment',
+	'Keyword',
+	'Identifier',
+	'Directive',
+	'Number',
+	'String',
+	'Op',
+	'Assign',
+	'Paren',
+	'Bracket',
+	'Colon',
+	'Comma',
+	'Dot',
+	'Ctor',
 ];
 
-/** @type {{ [key: string]: (el: HTMLElement) => undefined | Promise<undefined> }} */
+/** @type {{ [key: string]: (el: HTMLElement) => void | Promise<void> }} */
 const applyFns = {
 	timestamp: (el) => {
 		const timestamp = el.innerText;
@@ -314,15 +314,16 @@ const applyFns = {
 };
 
 /**
- * @param {HTMLElement} target
- * @param {string} code */
+ * @param {HTMLElement} target */
 async function fmt(target) {
 	const code = target.innerText;
 	const instance = await getFmtInstance();
 	const decoder = new TextDecoder('utf-8');
 	const fmt = modifyCode(instance, code, 'fmt');
-	const codeBytes = new TextEncoder('utf-8').encode(fmt);
+	if (typeof fmt !== "string") never()
+	const codeBytes = new TextEncoder().encode(fmt);
 	const tok = modifyCode(instance, fmt, 'tok');
+	if (!(tok instanceof Uint8Array)) never();
 	target.innerHTML = '';
 	let start = 0;
 	let kind = tok[0];
@@ -429,6 +430,7 @@ if (window.location.hostname === 'localhost') {
 			const code = "main:=fn():void{return}";
 			const inst = await getFmtInstance()
 			const fmtd = modifyCode(inst, code, "fmt") ?? never();
+			if (typeof fmtd !== "string") never();
 			const prev = modifyCode(inst, fmtd, "minify") ?? never();
 			if (code != prev) console.error(code, prev);
 		}
diff --git a/depell/src/main.rs b/depell/src/main.rs
index ce51368..0b234e0 100644
--- a/depell/src/main.rs
+++ b/depell/src/main.rs
@@ -64,6 +64,7 @@ async fn amain() {
         .route("/profile", get(Profile::page))
         .route("/profile-view", get(Profile::get))
         .route("/profile/:name", get(Profile::get_other_page))
+        .route("/profile/password", post(PasswordChange::post))
         .route("/profile-view/:name", get(Profile::get_other))
         .route("/post", get(Post::page))
         .route("/post-view", get(Post::get))
@@ -339,6 +340,70 @@ impl fmt::Display for Post {
     }
 }
 
+#[derive(Deserialize, Default)]
+struct PasswordChange {
+    old_password: String,
+    new_password: String,
+    #[serde(skip)]
+    error: Option<&'static str>,
+}
+
+impl PasswordChange {
+    async fn post(
+        session: Session,
+        axum::Form(mut change): axum::Form<PasswordChange>,
+    ) -> Html<String> {
+        db::with(|que| {
+            match que.authenticate.query_row((&session.name,), |r| r.get::<_, String>(1)) {
+                Ok(hash) if verify_password(&hash, &change.old_password).is_err() => {
+                    change.error = Some("invalid credentials");
+                }
+                Ok(_) => {
+                    let new_hashed = hash_password(&change.new_password);
+                    match que
+                        .change_passowrd
+                        .execute((new_hashed, &session.name))
+                        .log("execute update")
+                    {
+                        None => change.error = Some("intenal server error"),
+                        Some(0) => change.error = Some("password is incorrect"),
+                        Some(_) => {}
+                    }
+                }
+                Err(rusqlite::Error::QueryReturnedNoRows) => {
+                    change.error = Some("invalid credentials");
+                }
+                Err(e) => {
+                    log::error!("login queri failed: {e}");
+                    change.error = Some("internal server error");
+                }
+            }
+        });
+
+        if change.error.is_some() {
+            change.render(&session)
+        } else {
+            PasswordChange::default().render(&session)
+        }
+    }
+}
+
+impl Page for PasswordChange {
+    fn render_to_buf(self, _: &Session, buf: &mut String) {
+        let Self { old_password, new_password, error } = self;
+        write_html! { (buf)
+            <form "hx-post"="/profile/password" "hx-swap"="outerHTML">
+                if let Some(e) = error { <div class="error">e</div> }
+                <input name="old_password" type="password" autocomplete="old-password"
+                    placeholder="old password" value=old_password>
+                <input name="new_password" type="password" autocomplete="new-password" placeholder="new password"
+                    value=new_password>
+                <input type="submit" value="submit">
+            </form>
+        }
+    }
+}
+
 #[derive(Default)]
 struct Profile {
     other: Option<String>,
@@ -357,14 +422,19 @@ impl Profile {
 impl Page for Profile {
     fn render_to_buf(self, session: &Session, buf: &mut String) {
         db::with(|db| {
+            let name = self.other.as_ref().unwrap_or(&session.name);
             let iter = db
                 .get_user_posts
-                .query_map((self.other.as_ref().unwrap_or(&session.name),), Post::from_row)
+                .query_map((name,), Post::from_row)
                 .log("get user posts query")
                 .into_iter()
                 .flatten()
                 .filter_map(|p| p.log("user post row"));
-            write_html! { (buf)
+            write_html! { (*buf)
+                if name == &session.name {
+                    |b|{PasswordChange::default().render_to_buf(session, b)}
+                }
+
                 for post in iter {
                     !{post}
                 } else {
@@ -399,7 +469,7 @@ struct Login {
 
 impl PublicPage for Login {
     fn render_to_buf(self, buf: &mut String) {
-        let Login { name, password, error } = self;
+        let Self { name, password, error } = self;
         write_html! { (buf)
             <form "hx-post"="/login" "hx-swap"="outerHTML">
                 if let Some(e) = error { <div class="error">e</div> }
@@ -439,13 +509,12 @@ impl Login {
                 data.error = Some("invalid credentials");
             }
             Err(e) => {
-                log::error!("foo {e}");
+                log::error!("login queri failed: {e}");
                 data.error = Some("internal server error");
             }
         });
 
         if data.error.is_some() {
-            log::error!("what {:?}", data);
             Err(data.render())
         } else {
             Ok(AppendHeaders([
@@ -682,6 +751,7 @@ mod db {
     gen_queries! {
         pub struct Queries {
             register: "INSERT INTO user (name, password_hash) VALUES(?, ?)",
+            change_passowrd: "UPDATE user SET password_hash = ? WHERE name = ?",
             authenticate: "SELECT name, password_hash FROM user WHERE name = ?",
             login: "INSERT OR REPLACE INTO session (id, username, expiration) VALUES(?, ?, ?)",
             logout: "DELETE FROM session WHERE id = ?",