diff --git a/app/controllers/sessions_controller.rb b/app/controllers/sessions_controller.rb
index cccf977..a16afbb 100644
--- a/app/controllers/sessions_controller.rb
+++ b/app/controllers/sessions_controller.rb
@@ -2,7 +2,7 @@ class SessionsController < ApplicationController
   def new
     redirect_uri = url_for(action: :create, only_path: false)
     Rails.logger.info "Starting Slack OAuth flow with redirect URI: #{redirect_uri}"
-    redirect_to User.authorize_url(redirect_uri),
+    redirect_to User.authorize_url(redirect_uri, close_window: params[:close_window].present?),
                 host: "https://slack.com",
                 allow_other_host: true
   end
@@ -26,13 +26,22 @@ class SessionsController < ApplicationController
         OneTime::MigrateUserFromHackatimeJob.perform_later(@user.id)
       end
 
-      redirect_to root_path, notice: "Successfully signed in with Slack!"
+      state = JSON.parse(params[:state]) rescue {}
+      if state["close_window"]
+        redirect_to close_window_path
+      else
+        redirect_to root_path, notice: "Successfully signed in with Slack!"
+      end
     else
       Rails.logger.error "Failed to create/update user from Slack data"
       redirect_to root_path, alert: "Failed to sign in with Slack"
     end
   end
 
+  def close_window
+    render :close_window, layout: false
+  end
+
   def github_new
     unless current_user
       redirect_to root_path, alert: "Please sign in first to link your GitHub account"
diff --git a/app/models/user.rb b/app/models/user.rb
index bb30e1a..19c881d 100644
--- a/app/models/user.rb
+++ b/app/models/user.rb
@@ -183,11 +183,16 @@ class User < ApplicationRecord
       })
   end
 
-  def self.authorize_url(redirect_uri)
+  def self.authorize_url(redirect_uri, close_window: false)
+    state = {
+      token: SecureRandom.hex(24),
+      close_window: close_window
+    }.to_json
+
     params = {
       client_id: ENV["SLACK_CLIENT_ID"],
       redirect_uri: redirect_uri,
-      state: SecureRandom.hex(24),
+      state: state,
       user_scope: "users.profile:read,users.profile:write,users:read,users:read.email"
     }
 
diff --git a/app/views/sessions/close_window.html.erb b/app/views/sessions/close_window.html.erb
new file mode 100644
index 0000000..e333ebf
--- /dev/null
+++ b/app/views/sessions/close_window.html.erb
@@ -0,0 +1,7 @@
+<% content_for :title, "Successfully signed in!" %>
+<script>
+  setTimeout(function() {
+    window.close();
+  }, 1000);
+</script>
+<p>Successfully signed in! You can close this window.</p>
diff --git a/config/routes.rb b/config/routes.rb
index f53eaa2..bd08d67 100644
--- a/config/routes.rb
+++ b/config/routes.rb
@@ -50,6 +50,7 @@ Rails.application.routes.draw do
   get "/auth/github/callback", to: "sessions#github_create"
   post "/auth/email", to: "sessions#email", as: :email_auth
   get "/auth/token/:token", to: "sessions#token", as: :auth_token
+  get "/auth/close_window", to: "sessions#close_window", as: :close_window
   delete "signout", to: "sessions#destroy", as: "signout"
 
   resources :leaderboards, only: [ :index ]