diff --git a/i18n/en.toml b/i18n/en.toml
index 25c1ec4..aa2a93c 100644
--- a/i18n/en.toml
+++ b/i18n/en.toml
@@ -71,6 +71,7 @@ limited = "Limited"
 list = "List"
 load_image = "Load Image"
 lock = "Lock"
+login_captcha = "Login Captcha"
 medium = "Medium"
 members = "Members"
 message = "Message"
diff --git a/i18n/fr.toml b/i18n/fr.toml
index bbfbc50..1db40d5 100644
--- a/i18n/fr.toml
+++ b/i18n/fr.toml
@@ -71,6 +71,7 @@ limited = "Limité"
 list = "Liste"
 load_image = "Charger une image"
 lock = "Verrouiller"
+login_captcha = "Captcha de connexion"
 medium = "Moyen"
 members = "Membres"
 message = "Message" # @TODO
diff --git a/i18n/ja.toml b/i18n/ja.toml
index 5112a68..8aa6619 100644
--- a/i18n/ja.toml
+++ b/i18n/ja.toml
@@ -71,6 +71,7 @@ limited = "制限付き"
 list = "リスト"
 load_image = "画像を読み込む"
 lock = "ロック"
+login_captcha = "ログインキャプチャ"
 medium = "中"
 members = "メンバー"
 message = "Message" # @TODO
diff --git a/i18n/uk.toml b/i18n/uk.toml
index c7e0750..66998fe 100644
--- a/i18n/uk.toml
+++ b/i18n/uk.toml
@@ -72,6 +72,7 @@ list = "Список"
 load_image = "Відвантажити зображення"
 lock = "Заблокувати"
 medium = "Помірно"
+login_captcha = "Капча входу"
 members = "Учасники"
 message = "Повідомлення"
 mod = "Модерація"
diff --git a/i18n/zh_cn.toml b/i18n/zh_cn.toml
index ecbbd3c..77b2c2b 100644
--- a/i18n/zh_cn.toml
+++ b/i18n/zh_cn.toml
@@ -72,6 +72,7 @@ list = "列表"
 load_image = "加载图片"
 lock = "锁定"
 medium = "中等"
+login_captcha = "登录验证码"
 members = "成员"
 message = "Message" # @TODO
 mod = "管理员"
diff --git a/src/controller/admin.rs b/src/controller/admin.rs
index f120bd1..844b213 100644
--- a/src/controller/admin.rs
+++ b/src/controller/admin.rs
@@ -381,6 +381,7 @@ impl Default for SiteConfig {
             lang: "en".into(),
             tos_link: "https://en.wikipedia.org/wiki/WTFPL".into(),
             custom_footer_code: None,
+            login_captcha: None,
         }
     }
 }
diff --git a/src/controller/meta_handler.rs b/src/controller/meta_handler.rs
index a8207e3..ecc1a40 100644
--- a/src/controller/meta_handler.rs
+++ b/src/controller/meta_handler.rs
@@ -168,6 +168,7 @@ pub(super) struct PageData<'a> {
     pub(super) has_unread: bool,
     pub(super) lang: String,
     pub(super) custom_footer_code: Option<&'a str>,
+    pub(super) login_captcha: bool,
 }
 
 impl<'a> PageData<'a> {
@@ -194,6 +195,7 @@ impl<'a> PageData<'a> {
             site_description,
             site_name: &site_config.site_name,
             title,
+            login_captcha: site_config.login_captcha.unwrap_or(false),
         }
     }
 }
diff --git a/src/controller/mod.rs b/src/controller/mod.rs
index 0f7c53f..3c54ea8 100644
--- a/src/controller/mod.rs
+++ b/src/controller/mod.rs
@@ -529,6 +529,8 @@ pub(super) struct SiteConfig {
     tos_link: String,
     #[validate(skip)]
     custom_footer_code: Option<String>,
+    #[validate(skip)]
+    login_captcha: Option<bool>,
 }
 
 impl SiteConfig {
diff --git a/src/controller/user.rs b/src/controller/user.rs
index c6ce1d4..0127f84 100644
--- a/src/controller/user.rs
+++ b/src/controller/user.rs
@@ -877,8 +877,8 @@ pub(crate) const COOKIE_NAME: &str = "id";
 /// Form data: `/signin`
 #[derive(Deserialize)]
 pub(crate) struct FormSignin {
-    captcha_id: String,
-    captcha_value: String,
+    captcha_id: Option<String>,
+    captcha_value: Option<String>,
     password: String,
     remember: String,
     username: String,
@@ -925,12 +925,15 @@ pub(crate) async fn signin(
 
 /// `POST /signin`
 pub(crate) async fn signin_post(Form(input): Form<FormSignin>) -> impl IntoResponse {
-    let captcha_char = DB
-        .open_partition("captcha", Default::default())?
-        .take(&input.captcha_id)?
-        .ok_or(AppError::CaptchaError)?;
-    if captcha_char != input.captcha_value {
-        return Err(AppError::CaptchaError);
+    let site_config = SiteConfig::get(&DB)?;
+    if site_config.login_captcha == Some(true) {
+        let captcha_char = DB
+            .open_partition("captcha", Default::default())?
+            .take(&input.captcha_id.unwrap_or_default())?
+            .ok_or(AppError::CaptchaError)?;
+        if captcha_char != input.captcha_value.unwrap_or_default() {
+            return Err(AppError::CaptchaError);
+        }
     }
 
     let uid = match input.username.parse::<u32>() {
@@ -941,7 +944,6 @@ pub(crate) async fn signin_post(Form(input): Form<FormSignin>) -> impl IntoRespo
     };
     let user: User = get_one(&DB, "users", uid)?;
     if check_password(&input.password, &user.password_hash) {
-        let site_config = SiteConfig::get(&DB)?;
         if site_config.read_only && Role::from(user.role) != Role::Admin {
             return Err(AppError::ReadOnly);
         }
diff --git a/templates/admin.html b/templates/admin.html
index 2bda9ca..af61820 100644
--- a/templates/admin.html
+++ b/templates/admin.html
@@ -283,6 +283,26 @@
             </div>
         </div>
 
+        <div class="field is-horizontal">
+            <div class="field-label is-normal">
+                <label class="label" for="login_captcha">{{ "login_captcha"|l10n(page_data.lang) }}</label>
+            </div>
+            <div class="field-body">
+                <div class="field">
+                    <div class="control">
+                        {% match site_config.login_captcha %}
+                        {% when Some(true) %}
+                        <label class="radio"><input type="radio" name="login_captcha" value="true" checked autocomplete="off" /> {{ "yes"|l10n(page_data.lang) }}</label>
+                        <label class="radio"><input type="radio" name="login_captcha" value="false" autocomplete="off" /> {{ "no"|l10n(page_data.lang) }}</label>
+                        {% else %}
+                        <label class="radio"><input type="radio" name="login_captcha" value="true" autocomplete="off" /> {{ "yes"|l10n(page_data.lang) }}</label>
+                        <label class="radio"><input type="radio" name="login_captcha" value="false" checked autocomplete="off" /> {{ "no"|l10n(page_data.lang) }}</label>
+                        {% endmatch %}
+                    </div>
+                </div>
+            </div>
+        </div>
+
         <div class="field is-horizontal">
             <div class="field-label"></div>
             <div class="field-body">
diff --git a/templates/signin.html b/templates/signin.html
index 7a1ecd0..930b665 100644
--- a/templates/signin.html
+++ b/templates/signin.html
@@ -28,6 +28,7 @@
                 </div>
             </div>
 
+            {% if page_data.login_captcha %}
             <div>
                 <img src="data:image/png;base64,{{captcha_image}}" alt="captcha" class="captcha" />
             </div>
@@ -39,6 +40,7 @@
             </div>
 
             <input type="hidden" id="captcha_id" name="captcha_id" value="{{captcha_id}}">
+            {% endif %}
 
             <div class="field">
                 <label for="remember" class="label">{{ "stay_logged_in"|l10n(page_data.lang) }}</label>