diff --git a/app/views/about/_logged_in.html.haml b/app/views/about/_logged_in.html.haml
new file mode 100644
index 000000000..e1bcfffb3
--- /dev/null
+++ b/app/views/about/_logged_in.html.haml
@@ -0,0 +1,10 @@
+.simple_form
+  %p.lead= t('about.logged_in_as_html', username: content_tag(:strong, current_account.username))
+
+  .actions
+    = link_to t('about.continue_to_web'), root_url, class: 'button button-primary'
+
+.form-footer
+  %ul.no-list
+    %li= link_to t('about.get_apps'), 'https://joinmastodon.org/apps', target: '_blank', rel: 'noopener noreferrer'
+    %li= link_to t('auth.logout'), destroy_user_session_path, data: { method: :delete }
diff --git a/app/views/about/_registration.html.haml b/app/views/about/_registration.html.haml
index e4d614d71..b452e4936 100644
--- a/app/views/about/_registration.html.haml
+++ b/app/views/about/_registration.html.haml
@@ -1,17 +1,20 @@
-.simple_form__overlay-area{ class: (closed_registrations? && @instance_presenter.closed_registrations_message.present?) ? 'simple_form__overlay-area__blurred' : '' }
+- disabled = closed_registrations? || omniauth_only? || current_account.present?
+- show_message = disabled && (current_user.present? || @instance_presenter.closed_registrations_message.present?)
+
+.simple_form__overlay-area{ class: show_message ? 'simple_form__overlay-area__blurred' : '' }
   = simple_form_for(new_user, url: user_registration_path, namespace: 'registration', html: { novalidate: false }) do |f|
     %p.lead= t('about.federation_hint_html', instance: content_tag(:strong, site_hostname))
 
     .fields-group
       = f.simple_fields_for :account do |account_fields|
-        = account_fields.input :username, wrapper: :with_label, label: false, required: true, input_html: { 'aria-label' => t('simple_form.labels.defaults.username'), :autocomplete => 'off', placeholder: t('simple_form.labels.defaults.username'), pattern: '[a-zA-Z0-9_]+', maxlength: 30 }, append: "@#{site_hostname}", hint: false, disabled: closed_registrations?
+        = account_fields.input :username, wrapper: :with_label, label: false, required: true, input_html: { 'aria-label' => t('simple_form.labels.defaults.username'), :autocomplete => 'off', placeholder: t('simple_form.labels.defaults.username'), pattern: '[a-zA-Z0-9_]+', maxlength: 30 }, append: "@#{site_hostname}", hint: false, disabled: disabled
 
-      = f.input :email, placeholder: t('simple_form.labels.defaults.email'), required: true, input_html: { 'aria-label' => t('simple_form.labels.defaults.email'), :autocomplete => 'off' }, hint: false, disabled: closed_registrations?
-      = f.input :password, placeholder: t('simple_form.labels.defaults.password'), required: true, input_html: { 'aria-label' => t('simple_form.labels.defaults.password'), :autocomplete => 'off', :minlength => User.password_length.first, :maxlength => User.password_length.last }, hint: false, disabled: closed_registrations?
-      = f.input :password_confirmation, placeholder: t('simple_form.labels.defaults.confirm_password'), required: true, input_html: { 'aria-label' => t('simple_form.labels.defaults.confirm_password'), :autocomplete => 'off' }, hint: false, disabled: closed_registrations?
+      = f.input :email, placeholder: t('simple_form.labels.defaults.email'), required: true, input_html: { 'aria-label' => t('simple_form.labels.defaults.email'), :autocomplete => 'off' }, hint: false, disabled: disabled
+      = f.input :password, placeholder: t('simple_form.labels.defaults.password'), required: true, input_html: { 'aria-label' => t('simple_form.labels.defaults.password'), :autocomplete => 'off', :minlength => User.password_length.first, :maxlength => User.password_length.last }, hint: false, disabled: disabled
+      = f.input :password_confirmation, placeholder: t('simple_form.labels.defaults.confirm_password'), required: true, input_html: { 'aria-label' => t('simple_form.labels.defaults.confirm_password'), :autocomplete => 'off' }, hint: false, disabled: disabled
 
-      = f.input :confirm_password, as: :string, placeholder: t('simple_form.labels.defaults.honeypot', label: t('simple_form.labels.defaults.password')), required: false, input_html: { 'aria-label' => t('simple_form.labels.defaults.honeypot', label: t('simple_form.labels.defaults.password')), :autocomplete => 'off' }, hint: false, disabled: closed_registrations?
-      = f.input :website, as: :url, placeholder: t('simple_form.labels.defaults.honeypot', label: 'Website'), required: false, input_html: { 'aria-label' => t('simple_form.labels.defaults.honeypot', label: 'Website'), :autocomplete => 'off' }, hint: false, disabled: closed_registrations?
+      = f.input :confirm_password, as: :string, placeholder: t('simple_form.labels.defaults.honeypot', label: t('simple_form.labels.defaults.password')), required: false, input_html: { 'aria-label' => t('simple_form.labels.defaults.honeypot', label: t('simple_form.labels.defaults.password')), :autocomplete => 'off' }, hint: false, disabled: disabled
+      = f.input :website, as: :url, placeholder: t('simple_form.labels.defaults.honeypot', label: 'Website'), required: false, input_html: { 'aria-label' => t('simple_form.labels.defaults.honeypot', label: 'Website'), :autocomplete => 'off' }, hint: false, disabled: disabled
 
     - if approved_registrations?
       .fields-group
@@ -19,13 +22,16 @@
           = invite_request_fields.input :text, as: :text, wrapper: :with_block_label, required: Setting.require_invite_text
 
     .fields-group
-      = f.input :agreement, as: :boolean, wrapper: :with_label, label: t('auth.checkbox_agreement_html', rules_path: about_more_path, terms_path: terms_path), required: true, disabled: closed_registrations?
+      = f.input :agreement, as: :boolean, wrapper: :with_label, label: t('auth.checkbox_agreement_html', rules_path: about_more_path, terms_path: terms_path), required: true, disabled: disabled
 
     .actions
-      = f.button :button, sign_up_message, type: :submit, class: 'button button-primary', disabled: closed_registrations?
+      = f.button :button, sign_up_message, type: :submit, class: 'button button-primary', disabled: disabled
 
-  - if closed_registrations? && @instance_presenter.closed_registrations_message.present?
+  - if show_message
     .simple_form__overlay-area__overlay
       .simple_form__overlay-area__overlay__content.rich-formatting
         .block-icon= fa_icon 'warning'
-        = @instance_presenter.closed_registrations_message.html_safe
+        - if current_account.present?
+          = t('about.logout_before_registering')
+        - else
+          = @instance_presenter.closed_registrations_message.html_safe
diff --git a/app/views/about/show.html.haml b/app/views/about/show.html.haml
index 6ae9e6ae0..321440096 100644
--- a/app/views/about/show.html.haml
+++ b/app/views/about/show.html.haml
@@ -46,7 +46,10 @@
 
     .landing__grid__column.landing__grid__column-login
       .box-widget
-        = render 'login'
+        - if current_user.present?
+          = render 'logged_in'
+        - else
+          = render 'login'
 
       .hero-widget
         .hero-widget__img
diff --git a/config/locales/en.yml b/config/locales/en.yml
index 6a5594185..98a07aa6a 100644
--- a/config/locales/en.yml
+++ b/config/locales/en.yml
@@ -16,6 +16,7 @@ en:
     contact: Contact
     contact_missing: Not set
     contact_unavailable: N/A
+    continue_to_web: Continue to web app
     discover_users: Discover users
     documentation: Documentation
     federation_hint_html: With an account on %{instance} you'll be able to follow people on any Mastodon server and beyond.
@@ -25,6 +26,8 @@ en:
       This account is a virtual actor used to represent the server itself and not any individual user.
       It is used for federation purposes and should not be blocked unless you want to block the whole instance, in which case you should use a domain block.
     learn_more: Learn more
+    logged_in_as_html: You are currently logged in as %{username}.
+    logout_before_registering: You are already logged in.
     privacy_policy: Privacy policy
     rules: Server rules
     rules_html: 'Below is a summary of rules you need to follow if you want to have an account on this server of Mastodon:'
diff --git a/spec/views/about/show.html.haml_spec.rb b/spec/views/about/show.html.haml_spec.rb
index 1c2f5eee9..4eab97da9 100644
--- a/spec/views/about/show.html.haml_spec.rb
+++ b/spec/views/about/show.html.haml_spec.rb
@@ -8,6 +8,7 @@ describe 'about/show.html.haml', without_verify_partial_doubles: true do
     allow(view).to receive(:site_title).and_return('example site')
     allow(view).to receive(:new_user).and_return(User.new)
     allow(view).to receive(:use_seamless_external_login?).and_return(false)
+    allow(view).to receive(:current_account).and_return(nil)
   end
 
   it 'has valid open graph tags' do